/*
 * Author: alessandro crugnola
 * alessandro.crugnola@gmail.com
 * 
 * Fork based on the google opensource framework
 * 
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.pos.widgets.hlist;

import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v4.util.SparseArrayCompat;
import android.util.AttributeSet;
import android.util.Log;
import android.view.FocusFinder;
import android.view.KeyEvent;
import android.view.SoundEffectConstants;
import android.view.View;
import android.view.ViewDebug;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.widget.AbsListView;
import android.widget.ArrayAdapter;
import android.widget.Checkable;
import android.widget.ListAdapter;
import android.widget.RemoteViews.RemoteView;
import android.widget.WrapperListAdapter;

import com.pos.R;

import java.util.ArrayList;

/*
 * Implementation Notes:
 *
 * Some terminology:
 *
 *     index    - index of the items that are currently visible
 *     position - index of the items in the cursor
 */

/**
 * A view that shows items in a vertically scrolling list. The items come from
 * the {@link ListAdapter} associated with this view.
 * 
 * <p>
 * See the <a href="{@docRoot}guide/topics/ui/layout/listview.html">List
 * View</a> guide.
 * </p>
 * 
 * @attr ref android.R.styleable#ListView_entries
 * @attr ref android.R.styleable#ListView_divider
 * @attr ref android.R.styleable#ListView_dividerHeight
 * @attr ref android.R.styleable#ListView_headerDividersEnabled
 * @attr ref android.R.styleable#ListView_footerDividersEnabled
 */
@RemoteView
public class HListView extends AbsHListView {

	/**
	 * Used to indicate a no preference for a position type.
	 */
	static final int NO_POSITION = -1;

	/**
	 * When arrow scrolling, ListView will never scroll more than this factor
	 * times the height of the list.
	 */
	private static final float MAX_SCROLL_FACTOR = 0.33f;

	/**
	 * When arrow scrolling, need a certain amount of pixels to preview next
	 * items. This is usually the fading edge, but if that is small enough, we
	 * want to make sure we preview at least this many pixels.
	 */
	private static final int MIN_SCROLL_PREVIEW_PIXELS = 2;

	private static final String LOG_TAG = "HListView";

	/**
	 * A class that represents a fixed view in a list, for example a header at
	 * the top or a footer at the bottom.
	 */
	public static class FixedViewInfo {

		/** The view to add to the list */
		public View view;
		/**
		 * The data backing the view. This is returned from
		 * {@link ListAdapter#getItem(int)}.
		 */
		public Object data;
		/** <code>true</code> if the fixed view should be selectable in the list */
		public boolean isSelectable;
	}

	private ArrayList<FixedViewInfo> mHeaderViewInfos = new ArrayList<FixedViewInfo>();
	private ArrayList<FixedViewInfo> mFooterViewInfos = new ArrayList<FixedViewInfo>();

	Drawable mDivider;
	int mDividerWidth;
	int mMeasureWithChild;

	Drawable mOverScrollHeader;
	Drawable mOverScrollFooter;

	private boolean mIsCacheColorOpaque;
	private boolean mDividerIsOpaque;

	private boolean mHeaderDividersEnabled;
	private boolean mFooterDividersEnabled;

	private boolean mAreAllItemsSelectable = true;

	private boolean mItemsCanFocus = false;

	// used for temporary calculations.
	private final Rect mTempRect = new Rect();
	private Paint mDividerPaint;

	// the single allocated result per list view; kinda cheesey but avoids
	// allocating these thingies too often.
	private final ArrowScrollFocusResult mArrowScrollFocusResult = new ArrowScrollFocusResult();

	// Keeps focused children visible through resizes
	private FocusSelector mFocusSelector;

	public HListView(Context context) {
		this(context, null);
	}

	public HListView(Context context, AttributeSet attrs) {
		this(context, attrs, R.attr.hlv_listViewStyle);
	}

	public HListView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);

		if (LOG_ENABLED) {
			Log.i(LOG_TAG, "defStyle: " + defStyle);
		}

		final Resources.Theme theme = context.getTheme();
		TypedArray array = theme.obtainStyledAttributes(attrs,
				R.styleable.HListView, defStyle, 0);

		CharSequence[] entries = null;
		Drawable dividerDrawable = null;
		Drawable overscrollHeader = null;
		Drawable overscrollFooter = null;
		int dividerWidth = 0;

		boolean headerDividersEnabled = true;
		boolean footerDividersEnabled = true;
		int measureWithChild = -1;

		if (null != array) {
			entries = array.getTextArray(R.styleable.HListView_android_entries);
			dividerDrawable = array
					.getDrawable(R.styleable.HListView_android_divider);
			overscrollHeader = array
					.getDrawable(R.styleable.HListView_hlv_overScrollHeader);
			overscrollFooter = array
					.getDrawable(R.styleable.HListView_hlv_overScrollFooter);
			dividerWidth = array.getDimensionPixelSize(
					R.styleable.HListView_hlv_dividerWidth, 0);
			headerDividersEnabled = array.getBoolean(
					R.styleable.HListView_hlv_headerDividersEnabled, true);
			footerDividersEnabled = array.getBoolean(
					R.styleable.HListView_hlv_footerDividersEnabled, true);
			measureWithChild = array.getInteger(
					R.styleable.HListView_hlv_measureWithChild, -1);
			array.recycle();

			if (LOG_ENABLED) {
				Log.d(LOG_TAG, "divider: " + dividerDrawable);
				Log.d(LOG_TAG, "overscrollHeader: " + overscrollHeader);
				Log.d(LOG_TAG, "overscrollFooter: " + overscrollFooter);
				Log.d(LOG_TAG, "dividerWith: " + dividerWidth);
				Log.d(LOG_TAG, "headerDividersEnabled: "
						+ headerDividersEnabled);
				Log.d(LOG_TAG, "footerDividersEnabled: "
						+ footerDividersEnabled);
				Log.d(LOG_TAG, "measureWithChild: " + measureWithChild);
			}
		}

		if (entries != null) {
			setAdapter(new ArrayAdapter<CharSequence>(context,
					android.R.layout.simple_list_item_1, entries));
		}

		if (dividerDrawable != null) {
			// If a divider is specified use its intrinsic height for divider
			// height
			setDivider(dividerDrawable);
		}

		if (overscrollHeader != null) {
			setOverscrollHeader(overscrollHeader);
		}

		if (overscrollFooter != null) {
			setOverscrollFooter(overscrollFooter);
		}

		// Use the height specified, zero being the default
		if (dividerWidth != 0) {
			setDividerWidth(dividerWidth);
		}

		mHeaderDividersEnabled = headerDividersEnabled;
		mFooterDividersEnabled = footerDividersEnabled;
		mMeasureWithChild = measureWithChild;

	}

	/**
	 * @return The maximum amount a list view will scroll in response to an
	 *         arrow event.
	 */
	public int getMaxScrollAmount() {
		return (int) (MAX_SCROLL_FACTOR * (getRight() - getLeft()));
	}

	/**
	 * Make sure views are touching the top or bottom edge, as appropriate for
	 * our gravity
	 */
	private void adjustViewsLeftOrRight() {
		final int childCount = getChildCount();
		int delta;

		if (childCount > 0) {
			View child;

			if (!mStackFromRight) {
				// Uh-oh -- we came up short. Slide all views up to make them
				// align with the top
				child = getChildAt(0);
				delta = child.getLeft() - mListPadding.left;
				if (mFirstPosition != 0) {
					// It's OK to have some space above the first item if it is
					// part of the vertical spacing
					delta -= mDividerWidth;
				}
				if (delta < 0) {
					// We only are looking to see if we are too low, not too
					// high
					delta = 0;
				}
			} else {
				// we are too high, slide all views down to align with bottom
				child = getChildAt(childCount - 1);
				delta = child.getRight() - (getWidth() - mListPadding.right);

				if (mFirstPosition + childCount < mItemCount) {
					// It's OK to have some space below the last item if it is
					// part of the vertical spacing
					delta += mDividerWidth;
				}

				if (delta > 0) {
					delta = 0;
				}
			}

			if (delta != 0) {
				offsetChildrenLeftAndRight(-delta);
			}
		}
	}

	/**
	 * Add a fixed view to appear at the top of the list. If addHeaderView is
	 * called more than once, the views will appear in the order they were
	 * added. Views added using this call can take focus if they want.
	 * <p>
	 * NOTE: Call this before calling setAdapter. This is so ListView can wrap
	 * the supplied cursor with one that will also account for header and footer
	 * views.
	 *
	 * @param v
	 *            The view to add.
	 * @param data
	 *            Data to associate with this view
	 * @param isSelectable
	 *            whether the item is selectable
	 */
	public void addHeaderView(View v, Object data, boolean isSelectable) {

		if (mAdapter != null && !(mAdapter instanceof HeaderViewListAdapter)) {
			throw new IllegalStateException(
					"Cannot add header view to list -- setAdapter has already been called.");
		}

		FixedViewInfo info = new FixedViewInfo();
		info.view = v;
		info.data = data;
		info.isSelectable = isSelectable;
		mHeaderViewInfos.add(info);

		// in the case of re-adding a header view, or adding one later on,
		// we need to notify the observer
		if (mAdapter != null && mDataSetObserver != null) {
			mDataSetObserver.onChanged();
		}
	}

	/**
	 * Add a fixed view to appear at the top of the list. If addHeaderView is
	 * called more than once, the views will appear in the order they were
	 * added. Views added using this call can take focus if they want.
	 * <p>
	 * NOTE: Call this before calling setAdapter. This is so ListView can wrap
	 * the supplied cursor with one that will also account for header and footer
	 * views.
	 *
	 * @param v
	 *            The view to add.
	 */
	public void addHeaderView(View v) {
		addHeaderView(v, null, true);
	}

	@Override
	public int getHeaderViewsCount() {
		return mHeaderViewInfos.size();
	}

	/**
	 * Removes a previously-added header view.
	 *
	 * @param v
	 *            The view to remove
	 * @return true if the view was removed, false if the view was not a header
	 *         view
	 */
	public boolean removeHeaderView(View v) {
		if (mHeaderViewInfos.size() > 0) {
			boolean result = false;
			if (mAdapter != null
					&& ((HeaderViewListAdapter) mAdapter).removeHeader(v)) {
				if (mDataSetObserver != null) {
					mDataSetObserver.onChanged();
				}
				result = true;
			}
			removeFixedViewInfo(v, mHeaderViewInfos);
			return result;
		}
		return false;
	}

	private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) {
		int len = where.size();
		for (int i = 0; i < len; ++i) {
			FixedViewInfo info = where.get(i);
			if (info.view == v) {
				where.remove(i);
				break;
			}
		}
	}

	/**
	 * Add a fixed view to appear at the bottom of the list. If addFooterView is
	 * called more than once, the views will appear in the order they were
	 * added. Views added using this call can take focus if they want.
	 * <p>
	 * NOTE: Call this before calling setAdapter. This is so ListView can wrap
	 * the supplied cursor with one that will also account for header and footer
	 * views.
	 *
	 * @param v
	 *            The view to add.
	 * @param data
	 *            Data to associate with this view
	 * @param isSelectable
	 *            true if the footer view can be selected
	 */
	public void addFooterView(View v, Object data, boolean isSelectable) {

		// NOTE: do not enforce the adapter being null here, since unlike in
		// addHeaderView, it was never enforced here, and so existing apps are
		// relying on being able to add a footer and then calling setAdapter to
		// force creation of the HeaderViewListAdapter wrapper

		FixedViewInfo info = new FixedViewInfo();
		info.view = v;
		info.data = data;
		info.isSelectable = isSelectable;
		mFooterViewInfos.add(info);

		// in the case of re-adding a footer view, or adding one later on,
		// we need to notify the observer
		if (mAdapter != null && mDataSetObserver != null) {
			mDataSetObserver.onChanged();
		}
	}

	/**
	 * Add a fixed view to appear at the bottom of the list. If addFooterView is
	 * called more than once, the views will appear in the order they were
	 * added. Views added using this call can take focus if they want.
	 * <p>
	 * NOTE: Call this before calling setAdapter. This is so ListView can wrap
	 * the supplied cursor with one that will also account for header and footer
	 * views.
	 *
	 *
	 * @param v
	 *            The view to add.
	 */
	public void addFooterView(View v) {
		addFooterView(v, null, true);
	}

	@Override
	public int getFooterViewsCount() {
		return mFooterViewInfos.size();
	}

	/**
	 * Removes a previously-added footer view.
	 *
	 * @param v
	 *            The view to remove
	 * @return true if the view was removed, false if the view was not a footer
	 *         view
	 */
	public boolean removeFooterView(View v) {
		if (mFooterViewInfos.size() > 0) {
			boolean result = false;
			if (mAdapter != null
					&& ((HeaderViewListAdapter) mAdapter).removeFooter(v)) {
				if (mDataSetObserver != null) {
					mDataSetObserver.onChanged();
				}
				result = true;
			}
			removeFixedViewInfo(v, mFooterViewInfos);
			return result;
		}
		return false;
	}

	/**
	 * Returns the adapter currently in use in this ListView. The returned
	 * adapter might not be the same adapter passed to
	 * {@link #setAdapter(ListAdapter)} but might be a
	 * {@link WrapperListAdapter}.
	 *
	 * @return The adapter currently used to display data in this ListView.
	 *
	 * @see #setAdapter(ListAdapter)
	 */
	@Override
	public ListAdapter getAdapter() {
		return mAdapter;
	}

	/**
	 * Sets the data behind this ListView.
	 *
	 * The adapter passed to this method may be wrapped by a
	 * {@link WrapperListAdapter}, depending on the ListView features currently
	 * in use. For instance, adding headers and/or footers will cause the
	 * adapter to be wrapped.
	 *
	 * @param adapter
	 *            The ListAdapter which is responsible for maintaining the data
	 *            backing this list and for producing a view to represent an
	 *            item in that data set.
	 *
	 * @see #getAdapter()
	 */
	@Override
	public void setAdapter(ListAdapter adapter) {
		if (mAdapter != null && mDataSetObserver != null) {
			mAdapter.unregisterDataSetObserver(mDataSetObserver);
		}

		resetList();
		mRecycler.clear();

		if (mHeaderViewInfos.size() > 0 || mFooterViewInfos.size() > 0) {
			mAdapter = new HeaderViewListAdapter(mHeaderViewInfos,
					mFooterViewInfos, adapter);
		} else {
			mAdapter = adapter;
		}

		mOldSelectedPosition = INVALID_POSITION;
		mOldSelectedColId = INVALID_COL_ID;

		// AbsListView#setAdapter will update choice mode states.
		super.setAdapter(adapter);

		if (mAdapter != null) {
			mAreAllItemsSelectable = mAdapter.areAllItemsEnabled();
			mOldItemCount = mItemCount;
			mItemCount = mAdapter.getCount();
			checkFocus();

			mDataSetObserver = new AdapterDataSetObserver();
			mAdapter.registerDataSetObserver(mDataSetObserver);

			mRecycler.setViewTypeCount(mAdapter.getViewTypeCount());

			int position;
			if (mStackFromRight) {
				position = lookForSelectablePosition(mItemCount - 1, false);
			} else {
				position = lookForSelectablePosition(0, true);
			}
			setSelectedPositionInt(position);
			setNextSelectedPositionInt(position);

			if (mItemCount == 0) {
				// Nothing selected
				checkSelectionChanged();
			}
		} else {
			mAreAllItemsSelectable = true;
			checkFocus();
			// Nothing selected
			checkSelectionChanged();
		}

		requestLayout();
	}

	/**
	 * The list is empty. Clear everything out.
	 */
	@Override
	protected void resetList() {
		// The parent's resetList() will remove all views from the layout so we
		// need to
		// cleanup the state of our footers and headers
		clearRecycledState(mHeaderViewInfos);
		clearRecycledState(mFooterViewInfos);

		super.resetList();

		mLayoutMode = LAYOUT_NORMAL;
	}

	private void clearRecycledState(ArrayList<FixedViewInfo> infos) {
		if (infos != null) {
			final int count = infos.size();

			for (int i = 0; i < count; i++) {
				final View child = infos.get(i).view;
				final LayoutParams p = (LayoutParams) child.getLayoutParams();
				if (p != null) {
					p.recycledHeaderFooter = false;
				}
			}
		}
	}

	/**
	 * @return Whether the list needs to show the top fading edge
	 */
	private boolean showingLeftFadingEdge() {
		final int listLeft = getScrollX() + mListPadding.left;
		return (mFirstPosition > 0) || (getChildAt(0).getLeft() > listLeft);
	}

	/**
	 * @return Whether the list needs to show the bottom fading edge
	 */
	private boolean showingRightFadingEdge() {
		final int childCount = getChildCount();
		final int rightOfRightChild = getChildAt(childCount - 1).getRight();
		final int lastVisiblePosition = mFirstPosition + childCount - 1;

		final int listRight = getScrollX() + getWidth() - mListPadding.right;

		return (lastVisiblePosition < mItemCount - 1)
				|| (rightOfRightChild < listRight);
	}

	@Override
	public boolean requestChildRectangleOnScreen(View child, Rect rect,
                                                 boolean immediate) {

		int rectLeftWithinChild = rect.left;

		// offset so rect is in coordinates of the this view
		rect.offset(child.getLeft(), child.getTop());
		rect.offset(-child.getScrollX(), -child.getScrollY());

		final int width = getWidth();
		int listUnfadedLeft = getScrollX();
		int listUnfadedRight = listUnfadedLeft + width;
		final int fadingEdge = getHorizontalFadingEdgeLength();

		if (showingLeftFadingEdge()) {
			// leave room for top fading edge as long as rect isn't at very top
			if ((mSelectedPosition > 0) || (rectLeftWithinChild > fadingEdge)) {
				listUnfadedLeft += fadingEdge;
			}
		}

		int childCount = getChildCount();
		int rightOfRightChild = getChildAt(childCount - 1).getRight();

		if (showingRightFadingEdge()) {
			// leave room for bottom fading edge as long as rect isn't at very
			// bottom
			if ((mSelectedPosition < mItemCount - 1)
					|| (rect.right < (rightOfRightChild - fadingEdge))) {
				listUnfadedRight -= fadingEdge;
			}
		}

		int scrollXDelta = 0;

		if (rect.right > listUnfadedRight && rect.left > listUnfadedLeft) {
			// need to MOVE DOWN to get it in view: move down just enough so
			// that the entire rectangle is in view (or at least the first
			// screen size chunk).

			if (rect.width() > width) {
				// just enough to get screen size chunk on
				scrollXDelta += (rect.left - listUnfadedLeft);
			} else {
				// get entire rect at bottom of screen
				scrollXDelta += (rect.right - listUnfadedRight);
			}

			// make sure we aren't scrolling beyond the end of our children
			int distanceToRight = rightOfRightChild - listUnfadedRight;
			scrollXDelta = Math.min(scrollXDelta, distanceToRight);
		} else if (rect.left < listUnfadedLeft && rect.right < listUnfadedRight) {
			// need to MOVE UP to get it in view: move up just enough so that
			// entire rectangle is in view (or at least the first screen
			// size chunk of it).

			if (rect.width() > width) {
				// screen size chunk
				scrollXDelta -= (listUnfadedRight - rect.right);
			} else {
				// entire rect at top
				scrollXDelta -= (listUnfadedLeft - rect.left);
			}

			// make sure we aren't scrolling any further than the top our
			// children
			int left = getChildAt(0).getLeft();
			int deltaToLeft = left - listUnfadedLeft;
			scrollXDelta = Math.max(scrollXDelta, deltaToLeft);
		}

		final boolean scroll = scrollXDelta != 0;
		if (scroll) {
			scrollListItemsBy(-scrollXDelta);
			positionSelector(INVALID_POSITION, child);
			mSelectedLeft = child.getTop();
			invalidate();
		}
		return scroll;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected void fillGap(boolean down) {
		final int count = getChildCount();
		if (down) {
			int paddingLeft = 0;
			// if ( ( mGroupFlags & CLIP_TO_PADDING_MASK ) ==
			// CLIP_TO_PADDING_MASK ) {
			// paddingTop = getListPaddingTop();
			// }
			final int startOffset = count > 0 ? getChildAt(count - 1)
					.getRight() + mDividerWidth : paddingLeft;
			fillRight(mFirstPosition + count, startOffset);
			correctTooWide(getChildCount());
		} else {
			int paddingRight = 0;
			// if ( ( mGroupFlags & CLIP_TO_PADDING_MASK ) ==
			// CLIP_TO_PADDING_MASK ) {
			// paddingBottom = getListPaddingBottom();
			// }
			final int startOffset = count > 0 ? getChildAt(0).getLeft()
					- mDividerWidth : getWidth() - paddingRight;
			fillLeft(mFirstPosition - 1, startOffset);
			correctTooSmall(getChildCount());
		}
	}

	/**
	 * Fills the list from pos down to the end of the list view.
	 *
	 * @param pos
	 *            The first position to put in the list
	 *
	 * @param nextLeft
	 *            The location where the left of the item associated with pos
	 *            should be drawn
	 *
	 * @return The view that is currently selected, if it happens to be in the
	 *         range that we draw.
	 */
	private View fillRight(int pos, int nextLeft) {
		View selectedView = null;

		int end = (getRight() - getLeft());
		// if ( ( mGroupFlags & CLIP_TO_PADDING_MASK ) == CLIP_TO_PADDING_MASK )
		// {
		// end -= mListPadding.bottom;
		// }

		while (nextLeft < end && pos < mItemCount) {
			// is this the selected item?
			boolean selected = pos == mSelectedPosition;
			View child = makeAndAddView(pos, nextLeft, true, mListPadding.top,
					selected);

			nextLeft = child.getRight() + mDividerWidth;
			if (selected) {
				selectedView = child;
			}
			pos++;
		}

		setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount()
				- 1);
		return selectedView;
	}

	/**
	 * Fills the list from pos up to the top of the list view.
	 *
	 * @param pos
	 *            The first position to put in the list
	 *
	 * @param nextRight
	 *            The location where the right of the item associated with pos
	 *            should be drawn
	 *
	 * @return The view that is currently selected
	 */
	private View fillLeft(int pos, int nextRight) {
		View selectedView = null;

		int end = 0;
		// if ( ( mGroupFlags & CLIP_TO_PADDING_MASK ) == CLIP_TO_PADDING_MASK )
		// {
		// end = mListPadding.top;
		// }

		while (nextRight > end && pos >= 0) {
			// is this the selected item?
			boolean selected = pos == mSelectedPosition;
			View child = makeAndAddView(pos, nextRight, false,
					mListPadding.top, selected);
			nextRight = child.getLeft() - mDividerWidth;
			if (selected) {
				selectedView = child;
			}
			pos--;
		}

		mFirstPosition = pos + 1;
		setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount()
				- 1);
		return selectedView;
	}

	/**
	 * Fills the list from top to bottom, starting with mFirstPosition
	 *
	 * @param nextLeft
	 *            The location where the left of the first item should be drawn
	 *
	 * @return The view that is currently selected
	 */
	private View fillFromLeft(int nextLeft) {
		mFirstPosition = Math.min(mFirstPosition, mSelectedPosition);
		mFirstPosition = Math.min(mFirstPosition, mItemCount - 1);
		if (mFirstPosition < 0) {
			mFirstPosition = 0;
		}
		return fillRight(mFirstPosition, nextLeft);
	}

	/**
	 * Put mSelectedPosition in the middle of the screen and then build up and
	 * down from there. This method forces mSelectedPosition to the center.
	 *
	 * @param childrenLeft
	 *            Left of the area in which children can be drawn, as measured
	 *            in pixels
	 * @param childrenRight
	 *            Right of the area in which children can be drawn, as measured
	 *            in pixels
	 * @return Currently selected view
	 */
	private View fillFromMiddle(int childrenLeft, int childrenRight) {
		int width = childrenRight - childrenLeft;

		int position = reconcileSelectedPosition();

		View sel = makeAndAddView(position, childrenLeft, true,
				mListPadding.top, true);
		mFirstPosition = position;

		int selWidth = sel.getMeasuredWidth();
		if (selWidth <= width) {
			sel.offsetLeftAndRight((width - selWidth) / 2);
		}

		fillBeforeAndAfter(sel, position);

		if (!mStackFromRight) {
			correctTooWide(getChildCount());
		} else {
			correctTooSmall(getChildCount());
		}

		return sel;
	}

	/**
	 * Once the selected view as been placed, fill up the visible area above and
	 * below it.
	 *
	 * @param sel
	 *            The selected view
	 * @param position
	 *            The position corresponding to sel
	 */
	private void fillBeforeAndAfter(View sel, int position) {
		final int dividerWidth = mDividerWidth;
		if (!mStackFromRight) {
			fillLeft(position - 1, sel.getLeft() - dividerWidth);
			adjustViewsLeftOrRight();
			fillRight(position + 1, sel.getRight() + dividerWidth);
		} else {
			fillRight(position + 1, sel.getRight() + dividerWidth);
			adjustViewsLeftOrRight();
			fillLeft(position - 1, sel.getLeft() - dividerWidth);
		}
	}

	/**
	 * Fills the grid based on positioning the new selection at a specific
	 * location. The selection may be moved so that it does not intersect the
	 * faded edges. The grid is then filled upwards and downwards from there.
	 *
	 * @param selectedLeft
	 *            Where the selected item should be
	 * @param childrenLeft
	 *            Where to start drawing children
	 * @param childrenRight
	 *            Last pixel where children can be drawn
	 * @return The view that currently has selection
	 */
	private View fillFromSelection(int selectedLeft, int childrenLeft,
                                   int childrenRight) {
		int fadingEdgeLength = getHorizontalFadingEdgeLength();
		final int selectedPosition = mSelectedPosition;

		View sel;

		final int leftSelectionPixel = getLeftSelectionPixel(childrenLeft,
				fadingEdgeLength, selectedPosition);
		final int rightSelectionPixel = getRightSelectionPixel(childrenRight,
				fadingEdgeLength, selectedPosition);

		sel = makeAndAddView(selectedPosition, selectedLeft, true,
				mListPadding.top, true);

		// Some of the newly selected item extends below the bottom of the list
		if (sel.getRight() > rightSelectionPixel) {
			// Find space available above the selection into which we can scroll
			// upwards
			final int spaceBefore = sel.getLeft() - leftSelectionPixel;

			// Find space required to bring the bottom of the selected item
			// fully into view
			final int spaceAfter = sel.getRight() - rightSelectionPixel;
			final int offset = Math.min(spaceBefore, spaceAfter);

			// Now offset the selected item to get it into view
			sel.offsetLeftAndRight(-offset);
		} else if (sel.getLeft() < leftSelectionPixel) {
			// Find space required to bring the top of the selected item fully
			// into view
			final int spaceBefore = leftSelectionPixel - sel.getLeft();

			// Find space available below the selection into which we can scroll
			// downwards
			final int spaceAfter = rightSelectionPixel - sel.getRight();
			final int offset = Math.min(spaceBefore, spaceAfter);

			// Offset the selected item to get it into view
			sel.offsetLeftAndRight(offset);
		}

		// Fill in views above and below
		fillBeforeAndAfter(sel, selectedPosition);

		if (!mStackFromRight) {
			correctTooWide(getChildCount());
		} else {
			correctTooSmall(getChildCount());
		}

		return sel;
	}

	/**
	 * Calculate the bottom-most pixel we can draw the selection into
	 *
	 * @param childrenRight
	 *            Right pixel were children can be drawn
	 * @param fadingEdgeLength
	 *            Length of the fading edge in pixels, if present
	 * @param selectedPosition
	 *            The position that will be selected
	 * @return The bottom-most pixel we can draw the selection into
	 */
	private int getRightSelectionPixel(int childrenRight, int fadingEdgeLength,
			int selectedPosition) {
		int rightSelectionPixel = childrenRight;
		if (selectedPosition != mItemCount - 1) {
			rightSelectionPixel -= fadingEdgeLength;
		}
		return rightSelectionPixel;
	}

	/**
	 * Calculate the left-most pixel we can draw the selection into
	 *
	 * @param childrenLeft
	 *            Left pixel were children can be drawn
	 * @param fadingEdgeLength
	 *            Length of the fading edge in pixels, if present
	 * @param selectedPosition
	 *            The position that will be selected
	 * @return The left-most pixel we can draw the selection into
	 */
	private int getLeftSelectionPixel(int childrenLeft, int fadingEdgeLength,
			int selectedPosition) {
		// first pixel we can draw the selection into
		int leftSelectionPixel = childrenLeft;
		if (selectedPosition > 0) {
			leftSelectionPixel += fadingEdgeLength;
		}
		return leftSelectionPixel;
	}

	/**
	 * Smoothly scroll to the specified adapter position. The view will scroll
	 * such that the indicated position is displayed.
	 *
	 * @param position
	 *            Scroll to this adapter position.
	 */
	@Override
	public void smoothScrollToPosition(int position) {
		super.smoothScrollToPosition(position);
	}

	/**
	 * Smoothly scroll to the specified adapter position offset. The view will
	 * scroll such that the indicated position is displayed.
	 *
	 * @param offset
	 *            The amount to offset from the adapter position to scroll to.
	 */
	@Override
	public void smoothScrollByOffset(int offset) {
		super.smoothScrollByOffset(offset);
	}

	/**
	 * Fills the list based on positioning the new selection relative to the old
	 * selection. The new selection will be placed at, above, or below the
	 * location of the new selection depending on how the selection is moving.
	 * The selection will then be pinned to the visible part of the screen,
	 * excluding the edges that are faded. The list is then filled upwards and
	 * downwards from there.
	 *
	 * @param oldSel
	 *            The old selected view. Useful for trying to put the new
	 *            selection in the same place
	 * @param newSel
	 *            The view that is to become selected. Useful for trying to put
	 *            the new selection in the same place
	 * @param delta
	 *            Which way we are moving
	 * @param childrenLeft
	 *            Where to start drawing children
	 * @param childrenRight
	 *            Last pixel where children can be drawn
	 * @return The view that currently has selection
	 */
	private View moveSelection(View oldSel, View newSel, int delta,
                               int childrenLeft, int childrenRight) {
		int fadingEdgeLength = getHorizontalFadingEdgeLength();
		final int selectedPosition = mSelectedPosition;

		View sel;

		final int leftSelectionPixel = getLeftSelectionPixel(childrenLeft,
				fadingEdgeLength, selectedPosition);
		final int rightSelectionPixel = getRightSelectionPixel(childrenLeft,
				fadingEdgeLength, selectedPosition);

		if (delta > 0) {
			/*
			 * Case 1: Scrolling down.
			 */

			/*
			 * Before After | | | | +-------+ +-------+ | A | | A | | 1 | =>
			 * +-------+ +-------+ | B | | B | | 2 | +-------+ +-------+ | | | |
			 *
			 * Try to keep the top of the previously selected item where it was.
			 * oldSel = A sel = B
			 */

			// Put oldSel (A) where it belongs
			oldSel = makeAndAddView(selectedPosition - 1, oldSel.getLeft(),
					true, mListPadding.top, false);

			final int dividerWidth = mDividerWidth;

			// Now put the new selection (B) below that
			sel = makeAndAddView(selectedPosition, oldSel.getRight()
					+ dividerWidth, true, mListPadding.top, true);

			// Some of the newly selected item extends below the bottom of the
			// list
			if (sel.getRight() > rightSelectionPixel) {

				// Find space available above the selection into which we can
				// scroll upwards
				int spaceBefore = sel.getLeft() - leftSelectionPixel;

				// Find space required to bring the bottom of the selected item
				// fully into view
				int spaceAfter = sel.getRight() - rightSelectionPixel;

				// Don't scroll more than half the height of the list
				int halfHorizontalSpace = (childrenRight - childrenLeft) / 2;
				int offset = Math.min(spaceBefore, spaceAfter);
				offset = Math.min(offset, halfHorizontalSpace);

				// We placed oldSel, so offset that item
				oldSel.offsetLeftAndRight(-offset);
				// Now offset the selected item to get it into view
				sel.offsetLeftAndRight(-offset);
			}

			// Fill in views above and below
			if (!mStackFromRight) {
				fillLeft(mSelectedPosition - 2, sel.getLeft() - dividerWidth);
				adjustViewsLeftOrRight();
				fillRight(mSelectedPosition + 1, sel.getRight() + dividerWidth);
			} else {
				fillRight(mSelectedPosition + 1, sel.getRight() + dividerWidth);
				adjustViewsLeftOrRight();
				fillLeft(mSelectedPosition - 2, sel.getLeft() - dividerWidth);
			}
		} else if (delta < 0) {
			/*
			 * Case 2: Scrolling up.
			 */

			/*
			 * Before After | | | | +-------+ +-------+ | A | | A | +-------+ =>
			 * | 1 | | B | +-------+ | 2 | | B | +-------+ +-------+ | | | |
			 *
			 * Try to keep the top of the item about to become selected where it
			 * was. newSel = A olSel = B
			 */

			if (newSel != null) {
				// Try to position the top of newSel (A) where it was before it
				// was selected
				sel = makeAndAddView(selectedPosition, newSel.getLeft(), true,
						mListPadding.top, true);
			} else {
				// If (A) was not on screen and so did not have a view, position
				// it above the oldSel (B)
				sel = makeAndAddView(selectedPosition, oldSel.getLeft(), false,
						mListPadding.top, true);
			}

			// Some of the newly selected item extends above the top of the list
			if (sel.getLeft() < leftSelectionPixel) {
				// Find space required to bring the top of the selected item
				// fully into view
				int spaceBefore = leftSelectionPixel - sel.getLeft();

				// Find space available below the selection into which we can
				// scroll downwards
				int spaceAfter = rightSelectionPixel - sel.getRight();

				// Don't scroll more than half the height of the list
				int halfHorizontalSpace = (childrenRight - childrenLeft) / 2;
				int offset = Math.min(spaceBefore, spaceAfter);
				offset = Math.min(offset, halfHorizontalSpace);

				// Offset the selected item to get it into view
				sel.offsetLeftAndRight(offset);
			}

			// Fill in views above and below
			fillBeforeAndAfter(sel, selectedPosition);
		} else {

			int oldLeft = oldSel.getLeft();

			/*
			 * Case 3: Staying still
			 */
			sel = makeAndAddView(selectedPosition, oldLeft, true,
					mListPadding.top, true);

			// We're staying still...
			if (oldLeft < childrenLeft) {
				// ... but the top of the old selection was off screen.
				// (This can happen if the data changes size out from under us)
				int newRight = sel.getRight();
				if (newRight < childrenLeft + 20) {
					// Not enough visible -- bring it onscreen
					sel.offsetLeftAndRight(childrenLeft - sel.getLeft());
				}
			}

			// Fill in views above and below
			fillBeforeAndAfter(sel, selectedPosition);
		}

		return sel;
	}

	private class FocusSelector implements Runnable {

		private int mPosition;
		private int mPositionLeft;

		public FocusSelector setup(int position, int left) {
			mPosition = position;
			mPositionLeft = left;
			return this;
		}

		@Override
		public void run() {
			setSelectionFromLeft(mPosition, mPositionLeft);
		}
	}

	@Override
	protected void onSizeChanged(int w, int h, int oldw, int oldh) {
		if (getChildCount() > 0) {
			View focusedChild = getFocusedChild();
			if (focusedChild != null) {
				final int childPosition = mFirstPosition
						+ indexOfChild(focusedChild);
				final int childRight = focusedChild.getRight();
				final int offset = Math.max(0, childRight
						- (w - getPaddingLeft()));
				final int left = focusedChild.getLeft() - offset;
				if (mFocusSelector == null) {
					mFocusSelector = new FocusSelector();
				}
				post(mFocusSelector.setup(childPosition, left));
			}
		}
		super.onSizeChanged(w, h, oldw, oldh);
	}

	@TargetApi(11)
	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		// Sets up mListPadding
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);

		int widthMode = View.MeasureSpec.getMode(widthMeasureSpec);
		int heightMode = View.MeasureSpec.getMode(heightMeasureSpec);
		int widthSize = View.MeasureSpec.getSize(widthMeasureSpec);
		int heightSize = View.MeasureSpec.getSize(heightMeasureSpec);

		int childWidth = 0;
		int childHeight = 0;
		int childState = 0;

		mItemCount = mAdapter == null ? 0 : mAdapter.getCount();

		if (mItemCount > 0
				&& (widthMode == View.MeasureSpec.UNSPECIFIED || heightMode == View.MeasureSpec.UNSPECIFIED)) {
			if (LOG_ENABLED) {
				Log.d(LOG_TAG, "let's measure a scrap child");
			}

			final View child = obtainView(0, mIsScrap);

			measureScrapChildWidth(child, 0, heightMeasureSpec);

			childWidth = child.getMeasuredWidth();
			childHeight = child.getMeasuredHeight();

			if (android.os.Build.VERSION.SDK_INT >= 11) {
				childState = combineMeasuredStates(childState,
						child.getMeasuredState());
			}

			if (recycleOnMeasure()
					&& mRecycler.shouldRecycleViewType(((LayoutParams) child
							.getLayoutParams()).viewType)) {
				mRecycler.addScrapView(child, -1);
			}
		}

		if (heightMode == View.MeasureSpec.UNSPECIFIED) {
			heightSize = mListPadding.top + mListPadding.bottom + childHeight
					+ getHorizontalScrollbarHeight();
		} else if (heightMode == View.MeasureSpec.AT_MOST && mItemCount > 0
				&& mMeasureWithChild > -1) {

			// TODO: need a better way in case of "wrap_content"
			int[] result = measureWithLargeChildren(heightMeasureSpec,
					mMeasureWithChild, mMeasureWithChild, widthSize,
					heightSize, -1);
			heightSize = result[1];

		} else { // match_parent, dimension
			if (android.os.Build.VERSION.SDK_INT >= 11) {
				heightSize |= (childState & MEASURED_STATE_MASK);
			}
		}

		if (widthMode == View.MeasureSpec.UNSPECIFIED) {
			widthSize = mListPadding.left + mListPadding.right + childWidth
					+ getHorizontalFadingEdgeLength() * 2;
		}

		if (widthMode == View.MeasureSpec.AT_MOST) {
			widthSize = measureWidthOfChildren(heightMeasureSpec, 0,
					NO_POSITION, widthSize, -1);
		}

		if (LOG_ENABLED) {
			Log.d(LOG_TAG, "final size: " + widthSize + "x" + heightSize);
		}

		setMeasuredDimension(widthSize, heightSize);
		mHeightMeasureSpec = heightMeasureSpec;
	}

	private void measureScrapChildWidth(View child, int position,
                                        int heightMeasureSpec) {
		LayoutParams p = (LayoutParams) child.getLayoutParams();
		if (p == null) {
			p = (AbsHListView.LayoutParams) generateDefaultLayoutParams();
			child.setLayoutParams(p);
		}
		p.viewType = mAdapter.getItemViewType(position);
		p.forceAdd = true;

		int childHeightSpec = ViewGroup.getChildMeasureSpec(heightMeasureSpec,
				mListPadding.top + mListPadding.bottom, p.height);
		int lpWidth = p.width;
		int childWidthSpec;
		if (lpWidth > 0) {
			childWidthSpec = View.MeasureSpec.makeMeasureSpec(lpWidth,
					View.MeasureSpec.EXACTLY);
		} else {
			childWidthSpec = View.MeasureSpec.makeMeasureSpec(0,
					View.MeasureSpec.UNSPECIFIED);
		}
		child.measure(childWidthSpec, childHeightSpec);
	}

	public int[] measureChild(View child) {
		measureItem(child);

		int w = child.getMeasuredWidth();
		int h = child.getMeasuredHeight();

		return new int[] { w, h };
	}

	/**
	 * @return True to recycle the views used to measure this ListView in
	 *         UNSPECIFIED/AT_MOST modes, false otherwise.
	 * @hide
	 */
	@ViewDebug.ExportedProperty(category = "list")
	protected boolean recycleOnMeasure() {
		return true;
	}

	/**
	 * Measures the height of the given range of children (inclusive) and
	 * returns the height with this ListView's padding and divider heights
	 * included. If maxHeight is provided, the measuring will stop when the
	 * current height reaches maxHeight.
	 *
	 * @param heightMeasureSpec
	 *            The height measure spec to be given to a child's
	 *            {@link View#measure(int, int)}.
	 * @param startPosition
	 *            The position of the first child to be shown.
	 * @param endPosition
	 *            The (inclusive) position of the last child to be shown.
	 *            Specify {@link #NO_POSITION} if the last child should be the
	 *            last available child from the adapter.
	 * @param maxWidth
	 *            The maximum height that will be returned (if all the children
	 *            don't fit in this value, this value will be returned).
	 * @param disallowPartialChildPosition
	 *            In general, whether the returned height should only contain
	 *            entire children. This is more powerful--it is the first
	 *            inclusive position at which partial children will not be
	 *            allowed. Example: it looks nice to have at least 3 completely
	 *            visible children, and in portrait this will most likely fit;
	 *            but in landscape there could be times when even 2 children can
	 *            not be completely shown, so a value of 2 (remember, inclusive)
	 *            would be good (assuming startPosition is 0).
	 * @return The height of this ListView with the given children.
	 */
	final int measureWidthOfChildren(int heightMeasureSpec, int startPosition,
			int endPosition, final int maxWidth,
			int disallowPartialChildPosition) {
		if (LOG_ENABLED) {
			Log.i(LOG_TAG, "measureWidthOfChildren, from " + startPosition
					+ " to " + endPosition);
		}

		final ListAdapter adapter = mAdapter;
		if (adapter == null) {
			return mListPadding.left + mListPadding.right;
		}

		// Include the padding of the list
		int returnedWidth = mListPadding.left + mListPadding.right;
		final int dividerWidth = ((mDividerWidth > 0) && mDivider != null) ? mDividerWidth
				: 0;
		// The previous height value that was less than maxHeight and contained
		// no partial children
		int prevWidthWithoutPartialChild = 0;
		int i;
		View child;

		// mItemCount - 1 since endPosition parameter is inclusive
		endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1
				: endPosition;
		final AbsHListView.RecycleBin recycleBin = mRecycler;
		final boolean recyle = recycleOnMeasure();
		final boolean[] isScrap = mIsScrap;

		for (i = startPosition; i <= endPosition; ++i) {
			child = obtainView(i, isScrap);

			measureScrapChildWidth(child, i, heightMeasureSpec);

			if (i > 0) {
				// Count the divider for all but one child
				returnedWidth += dividerWidth;
			}

			// Recycle the view before we possibly return from the method
			if (recyle
					&& recycleBin.shouldRecycleViewType(((LayoutParams) child
							.getLayoutParams()).viewType)) {
				recycleBin.addScrapView(child, -1);
			}

			returnedWidth += child.getMeasuredWidth();

			if (returnedWidth >= maxWidth) {
				// We went over, figure out which height to return. If
				// returnedHeight > maxHeight,
				// then the i'th position did not fit completely.
				return (disallowPartialChildPosition >= 0) // Disallowing is
															// enabled (> -1)
						&& (i > disallowPartialChildPosition) // We've past the
																// min pos
						&& (prevWidthWithoutPartialChild > 0) // We have a prev
																// height
						&& (returnedWidth != maxWidth) // i'th child did not fit
														// completely
				? prevWidthWithoutPartialChild : maxWidth;
			}

			if ((disallowPartialChildPosition >= 0)
					&& (i >= disallowPartialChildPosition)) {
				prevWidthWithoutPartialChild = returnedWidth;
			}
		}

		// At this point, we went through the range of children, and they each
		// completely fit, so return the returnedHeight
		return returnedWidth;
	}

	final int[] measureWithLargeChildren(int heightMeasureSpec,
			int startPosition, int endPosition, final int maxWidth,
			final int maxHeight, int disallowPartialChildPosition) {
		if (LOG_ENABLED) {
			Log.i(LOG_TAG, "measureWithLargeChildren, from " + startPosition
					+ " to " + endPosition);
		}

		final ListAdapter adapter = mAdapter;
		if (adapter == null) {
			return new int[] { mListPadding.left + mListPadding.right,
					mListPadding.top + mListPadding.bottom };
		}

		// Include the padding of the list
		int returnedWidth = mListPadding.left + mListPadding.right;
		int returnedHeight = mListPadding.top + mListPadding.bottom;

		final int dividerWidth = ((mDividerWidth > 0) && mDivider != null) ? mDividerWidth
				: 0;

		int childWidth = 0;
		int childHeight = 0;

		int i;
		View child;

		// mItemCount - 1 since endPosition parameter is inclusive
		endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1
				: endPosition;
		final AbsHListView.RecycleBin recycleBin = mRecycler;
		final boolean recyle = recycleOnMeasure();
		final boolean[] isScrap = mIsScrap;

		for (i = startPosition; i <= endPosition; ++i) {
			child = obtainView(i, isScrap);

			measureScrapChildWidth(child, i, heightMeasureSpec);

			// Recycle the view before we possibly return from the method
			if (recyle
					&& recycleBin.shouldRecycleViewType(((LayoutParams) child
							.getLayoutParams()).viewType)) {
				recycleBin.addScrapView(child, -1);
			}

			childWidth = Math.max(childWidth, child.getMeasuredWidth()
					+ dividerWidth);
			childHeight = Math.max(childHeight, child.getMeasuredHeight());
		}

		returnedWidth += childWidth;
		returnedHeight += childHeight;

		return new int[] { Math.min(returnedWidth, maxWidth),
				Math.min(returnedHeight, maxHeight) };
	}

	@Override
	protected int findMotionCol(int x) {
		int childCount = getChildCount();
		if (childCount > 0) {
			if (!mStackFromRight) {
				for (int i = 0; i < childCount; i++) {
					View v = getChildAt(i);
					if (x <= v.getRight()) {
						return mFirstPosition + i;
					}
				}
			} else {
				for (int i = childCount - 1; i >= 0; i--) {
					View v = getChildAt(i);
					if (x >= v.getLeft()) {
						return mFirstPosition + i;
					}
				}
			}
		}
		return INVALID_POSITION;
	}

	/**
	 * Put a specific item at a specific location on the screen and then build
	 * up and down from there.
	 *
	 * @param position
	 *            The reference view to use as the starting point
	 * @param left
	 *            Pixel offset from the left of this view to the top of the
	 *            reference view.
	 *
	 * @return The selected view, or null if the selected view is outside the
	 *         visible area.
	 */
	private View fillSpecific(int position, int left) {
		boolean tempIsSelected = position == mSelectedPosition;
		View temp = makeAndAddView(position, left, true, mListPadding.top,
				tempIsSelected);
		// Possibly changed again in fillUp if we add rows above this one.
		mFirstPosition = position;

		View before;
		View after;

		final int dividerWidth = mDividerWidth;
		if (!mStackFromRight) {
			before = fillLeft(position - 1, temp.getLeft() - dividerWidth);
			// This will correct for the top of the first view not touching the
			// top of the list
			adjustViewsLeftOrRight();
			after = fillRight(position + 1, temp.getRight() + dividerWidth);
			int childCount = getChildCount();
			if (childCount > 0) {
				correctTooWide(childCount);
			}
		} else {
			after = fillRight(position + 1, temp.getRight() + dividerWidth);
			// This will correct for the bottom of the last view not touching
			// the bottom of the list
			adjustViewsLeftOrRight();
			before = fillLeft(position - 1, temp.getLeft() - dividerWidth);
			int childCount = getChildCount();
			if (childCount > 0) {
				correctTooSmall(childCount);
			}
		}

		if (tempIsSelected) {
			return temp;
		} else if (before != null) {
			return before;
		} else {
			return after;
		}
	}

	/**
	 * Check if we have dragged the right of the list too wide (we have pushed
	 * the left element off the left of the screen when we did not need to).
	 * Correct by sliding everything back down.
	 *
	 * @param childCount
	 *            Number of children
	 */
	private void correctTooWide(int childCount) {
		// First see if the last item is visible. If it is not, it is OK for the
		// top of the list to be pushed up.
		int lastPosition = mFirstPosition + childCount - 1;
		if (lastPosition == mItemCount - 1 && childCount > 0) {

			// Get the last child ...
			final View lastChild = getChildAt(childCount - 1);

			// ... and its bottom edge
			final int lastRight = lastChild.getRight();

			// This is bottom of our drawable area
			final int end = (getRight() - getLeft()) - mListPadding.right;

			// This is how far the bottom edge of the last view is from the
			// bottom of the
			// drawable area
			int rightOffset = end - lastRight;
			View firstChild = getChildAt(0);
			final int firstLeft = firstChild.getLeft();

			// Make sure we are 1) Too high, and 2) Either there are more rows
			// above the
			// first row or the first row is scrolled off the top of the
			// drawable area
			if (rightOffset > 0
					&& (mFirstPosition > 0 || firstLeft < mListPadding.top)) {
				if (mFirstPosition == 0) {
					// Don't pull the top too far down
					rightOffset = Math.min(rightOffset, mListPadding.top
							- firstLeft);
				}
				// Move everything down
				offsetChildrenLeftAndRight(rightOffset);
				if (mFirstPosition > 0) {
					// Fill the gap that was opened above mFirstPosition with
					// more rows, if
					// possible
					fillLeft(mFirstPosition - 1, firstChild.getLeft()
							- mDividerWidth);
					// Close up the remaining gap
					adjustViewsLeftOrRight();
				}

			}
		}
	}

	/**
	 * Check if we have dragged the right of the list too low (we have pushed
	 * the right element off the right of the screen when we did not need to).
	 * Correct by sliding everything back up.
	 *
	 * @param childCount
	 *            Number of children
	 */
	private void correctTooSmall(int childCount) {
		// First see if the first item is visible. If it is not, it is OK for
		// the
		// bottom of the list to be pushed down.
		if (mFirstPosition == 0 && childCount > 0) {

			// Get the first child ...
			final View firstChild = getChildAt(0);

			// ... and its top edge
			final int firstLeft = firstChild.getLeft();

			// This is top of our drawable area
			final int start = mListPadding.left;

			// This is bottom of our drawable area
			final int end = (getRight() - getLeft()) - mListPadding.right;

			// This is how far the top edge of the first view is from the top of
			// the
			// drawable area
			int leftOffset = firstLeft - start;
			View lastChild = getChildAt(childCount - 1);
			final int lastRight = lastChild.getRight();
			int lastPosition = mFirstPosition + childCount - 1;

			// Make sure we are 1) Too low, and 2) Either there are more rows
			// below the
			// last row or the last row is scrolled off the bottom of the
			// drawable area
			if (leftOffset > 0) {
				if (lastPosition < mItemCount - 1 || lastRight > end) {
					if (lastPosition == mItemCount - 1) {
						// Don't pull the bottom too far up
						leftOffset = Math.min(leftOffset, lastRight - end);
					}
					// Move everything up
					offsetChildrenLeftAndRight(-leftOffset);
					if (lastPosition < mItemCount - 1) {
						// Fill the gap that was opened below the last position
						// with more rows, if
						// possible
						fillRight(lastPosition + 1, lastChild.getRight()
								+ mDividerWidth);
						// Close up the remaining gap
						adjustViewsLeftOrRight();
					}
				} else if (lastPosition == mItemCount - 1) {
					adjustViewsLeftOrRight();
				}
			}
		}
	}

	@Override
	protected void layoutChildren() {
		final boolean blockLayoutRequests = mBlockLayoutRequests;
		if (!blockLayoutRequests) {
			mBlockLayoutRequests = true;
		} else {
			return;
		}

		try {
			super.layoutChildren();

			invalidate();

			if (mAdapter == null) {
				resetList();
				invokeOnItemScrollListener();
				return;
			}

			int childrenLeft = mListPadding.left;
			int childrenRight = getRight() - getLeft() - mListPadding.right;

			int childCount = getChildCount();
			int index = 0;
			int delta = 0;

			View sel;
			View oldSel = null;
			View oldFirst = null;
			View newSel = null;

			View focusLayoutRestoreView = null;

			// AccessibilityNodeInfo accessibilityFocusLayoutRestoreNode = null;
			// View accessibilityFocusLayoutRestoreView = null;
			// int accessibilityFocusPosition = INVALID_POSITION;

			// Remember stuff we will need down below
			switch (mLayoutMode) {
			case LAYOUT_SET_SELECTION:
				index = mNextSelectedPosition - mFirstPosition;
				if (index >= 0 && index < childCount) {
					newSel = getChildAt(index);
				}
				break;
			case LAYOUT_FORCE_LEFT:
			case LAYOUT_FORCE_RIGHT:
			case LAYOUT_SPECIFIC:
			case LAYOUT_SYNC:
				break;
			case LAYOUT_MOVE_SELECTION:
			default:
				// Remember the previously selected view
				index = mSelectedPosition - mFirstPosition;
				if (index >= 0 && index < childCount) {
					oldSel = getChildAt(index);
				}

				// Remember the previous first child
				oldFirst = getChildAt(0);

				if (mNextSelectedPosition >= 0) {
					delta = mNextSelectedPosition - mSelectedPosition;
				}

				// Caution: newSel might be null
				newSel = getChildAt(index + delta);
			}

			boolean dataChanged = mDataChanged;
			if (dataChanged) {
				handleDataChanged();
			}

			// Handle the empty set by removing all views that are visible
			// and calling it a day
			if (mItemCount == 0) {
				resetList();
				invokeOnItemScrollListener();
				return;
			} else if (mItemCount != mAdapter.getCount()) {
				throw new IllegalStateException(
						"The content of the adapter has changed but "
								+ "ListView did not receive a notification. Make sure the content of "
								+ "your adapter is not modified from a background thread, but only "
								+ "from the UI thread. [in ListView(" + getId()
								+ ", " + getClass() + ") with Adapter("
								+ mAdapter.getClass() + ")]");
			}

			setSelectedPositionInt(mNextSelectedPosition);

			// Pull all children into the RecycleBin.
			// These views will be reused if possible
			final int firstPosition = mFirstPosition;
			final RecycleBin recycleBin = mRecycler;

			// reset the focus restoration
			View focusLayoutRestoreDirectChild = null;

			// Don't put header or footer views into the Recycler. Those are
			// already cached in mHeaderViews;
			if (dataChanged) {
				for (int i = 0; i < childCount; i++) {
					recycleBin.addScrapView(getChildAt(i), firstPosition + i);
				}
			} else {
				recycleBin.fillActiveViews(childCount, firstPosition);
			}

			// take focus back to us temporarily to avoid the eventual
			// call to clear focus when removing the focused child below
			// from messing things up when ViewAncestor assigns focus back
			// to someone else
			final View focusedChild = getFocusedChild();
			if (focusedChild != null) {
				// TODO: in some cases focusedChild.getParent() == null

				// we can remember the focused view to restore after relayout if
				// the
				// data hasn't changed, or if the focused position is a header
				// or footer
				if (!dataChanged || isDirectChildHeaderOrFooter(focusedChild)) {
					focusLayoutRestoreDirectChild = focusedChild;
					// remember the specific view that had focus
					focusLayoutRestoreView = findFocus();
					if (focusLayoutRestoreView != null) {
						// tell it we are going to mess with it
						focusLayoutRestoreView.onStartTemporaryDetach();
					}
				}
				requestFocus();
			}

			/*
			 * // Remember which child, if any, had accessibility focus. final
			 * ViewRootImpl viewRootImpl = getViewRootImpl(); if ( viewRootImpl
			 * != null ) { final View accessFocusedView =
			 * viewRootImpl.getAccessibilityFocusedHost(); if (
			 * accessFocusedView != null ) { final View accessFocusedChild =
			 * findAccessibilityFocusedChild( accessFocusedView ); if (
			 * accessFocusedChild != null ) { if ( !dataChanged ||
			 * isDirectChildHeaderOrFooter( accessFocusedChild ) ) { // If the
			 * views won't be changing, try to maintain // focus on the current
			 * view host and (if // applicable) its virtual view.
			 * accessibilityFocusLayoutRestoreView = accessFocusedView;
			 * accessibilityFocusLayoutRestoreNode = viewRootImpl
			 * .getAccessibilityFocusedVirtualView(); } else { // Otherwise, try
			 * to maintain focus at the same // position.
			 * accessibilityFocusPosition = getPositionForView(
			 * accessFocusedChild ); } } } }
			 */

			// Clear out old views
			detachAllViewsFromParent();
			recycleBin.removeSkippedScrap();

			switch (mLayoutMode) {
			case LAYOUT_SET_SELECTION:
				if (newSel != null) {
					sel = fillFromSelection(newSel.getLeft(), childrenLeft,
							childrenRight);
				} else {
					sel = fillFromMiddle(childrenLeft, childrenRight);
				}
				break;
			case LAYOUT_SYNC:
				sel = fillSpecific(mSyncPosition, mSpecificLeft);
				break;
			case LAYOUT_FORCE_RIGHT:
				sel = fillLeft(mItemCount - 1, childrenRight);
				adjustViewsLeftOrRight();
				break;
			case LAYOUT_FORCE_LEFT:
				mFirstPosition = 0;
				sel = fillFromLeft(childrenLeft);
				adjustViewsLeftOrRight();
				break;
			case LAYOUT_SPECIFIC:
				sel = fillSpecific(reconcileSelectedPosition(), mSpecificLeft);
				break;
			case LAYOUT_MOVE_SELECTION:
				sel = moveSelection(oldSel, newSel, delta, childrenLeft,
						childrenRight);
				break;
			default:
				if (childCount == 0) {
					if (!mStackFromRight) {
						final int position = lookForSelectablePosition(0, true);
						setSelectedPositionInt(position);
						sel = fillFromLeft(childrenLeft);
					} else {
						final int position = lookForSelectablePosition(
								mItemCount - 1, false);
						setSelectedPositionInt(position);
						sel = fillLeft(mItemCount - 1, childrenRight);
					}
				} else {
					if (mSelectedPosition >= 0
							&& mSelectedPosition < mItemCount) {
						sel = fillSpecific(
								mSelectedPosition,
								oldSel == null ? childrenLeft : oldSel
										.getLeft());
					} else if (mFirstPosition < mItemCount) {
						sel = fillSpecific(
								mFirstPosition,
								oldFirst == null ? childrenLeft : oldFirst
										.getLeft());
					} else {
						sel = fillSpecific(0, childrenLeft);
					}
				}
				break;
			}

			// Flush any cached views that did not get reused above
			recycleBin.scrapActiveViews();

			if (sel != null) {
				// the current selected item should get focus if items
				// are focusable
				if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) {
					final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild
							&& focusLayoutRestoreView != null && focusLayoutRestoreView
								.requestFocus()) || sel.requestFocus();
					if (!focusWasTaken) {
						// selected item didn't take focus, fine, but still want
						// to make sure something else outside of the selected
						// view
						// has focus
						final View focused = getFocusedChild();
						if (focused != null) {
							focused.clearFocus();
						}
						positionSelector(INVALID_POSITION, sel);
					} else {
						sel.setSelected(false);
						mSelectorRect.setEmpty();
					}
				} else {
					positionSelector(INVALID_POSITION, sel);
				}
				mSelectedLeft = sel.getLeft();
			} else {
				if (mTouchMode > TOUCH_MODE_DOWN
						&& mTouchMode < TOUCH_MODE_SCROLL) {
					View child = getChildAt(mMotionPosition - mFirstPosition);
					if (child != null)
						positionSelector(mMotionPosition, child);
				} else {
					mSelectedLeft = 0;
					mSelectorRect.setEmpty();
				}

				// even if there is not selected position, we may need to
				// restore
				// focus (i.e. something focusable in touch mode)
				if (hasFocus() && focusLayoutRestoreView != null) {
					focusLayoutRestoreView.requestFocus();
				}
			}

			// Attempt to restore accessibility focus.
			// if ( accessibilityFocusLayoutRestoreNode != null ) {
			// accessibilityFocusLayoutRestoreNode.performAction(AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS
			// );
			// } else if ( accessibilityFocusLayoutRestoreView != null ) {
			// this method is marked as hidden. Shame on you google!
			// accessibilityFocusLayoutRestoreView.requestAccessibilityFocus();
			// } else if ( accessibilityFocusPosition != INVALID_POSITION ) {
			// Bound the position within the visible children.
			// final int position = MathUtils.constrain( (
			// accessibilityFocusPosition - mFirstPosition ), 0, (
			// getChildCount() - 1 ) );
			// final View restoreView = getChildAt( position );
			// if ( restoreView != null ) {
			// this method is marked as hidden. Shame on you google!
			// restoreView.requestAccessibilityFocus();
			// }
			// }

			// tell focus view we are done mucking with it, if it is still in
			// our view hierarchy.
			if (focusLayoutRestoreView != null
					&& focusLayoutRestoreView.getWindowToken() != null) {
				focusLayoutRestoreView.onFinishTemporaryDetach();
			}

			mLayoutMode = LAYOUT_NORMAL;
			mDataChanged = false;
			if (mPositionScrollAfterLayout != null) {
				post(mPositionScrollAfterLayout);
				mPositionScrollAfterLayout = null;
			}
			mNeedSync = false;
			setNextSelectedPositionInt(mSelectedPosition);

			updateScrollIndicators();

			if (mItemCount > 0) {
				checkSelectionChanged();
			}

			invokeOnItemScrollListener();
		} finally {
			if (!blockLayoutRequests) {
				mBlockLayoutRequests = false;
			}
		}
	}

	/**
	 * @param focusedView
	 *            the view that has accessibility focus.
	 * @return the direct child that contains accessibility focus.
	 */
	@SuppressWarnings("unused")
	private View findAccessibilityFocusedChild(View focusedView) {
		ViewParent viewParent = focusedView.getParent();
		while ((viewParent instanceof View) && (viewParent != this)) {
			focusedView = (View) viewParent;
			viewParent = viewParent.getParent();
		}
		if (!(viewParent instanceof View)) {
			return null;
		}
		return focusedView;
	}

	/**
	 * @param child
	 *            a direct child of this list.
	 * @return Whether child is a header or footer view.
	 */
	private boolean isDirectChildHeaderOrFooter(View child) {

		final ArrayList<FixedViewInfo> headers = mHeaderViewInfos;
		final int numHeaders = headers.size();
		for (int i = 0; i < numHeaders; i++) {
			if (child == headers.get(i).view) {
				return true;
			}
		}
		final ArrayList<FixedViewInfo> footers = mFooterViewInfos;
		final int numFooters = footers.size();
		for (int i = 0; i < numFooters; i++) {
			if (child == footers.get(i).view) {
				return true;
			}
		}
		return false;
	}

	/**
	 * Obtain the view and add it to our list of children. The view can be made
	 * fresh, converted from an unused view, or used as is if it was in the
	 * recycle bin.
	 *
	 * @param position
	 *            Logical position in the list
	 * @param x
	 *            Left or right edge of the view to add
	 * @param flow
	 *            If flow is true, align left edge to x. If false, align right
	 *            edge to x.
	 * @param childrenTop
	 *            Top edge where children should be positioned
	 * @param selected
	 *            Is this position selected?
	 * @return View that was added
	 */
	private View makeAndAddView(int position, int x, boolean flow,
                                int childrenTop, boolean selected) {
		View child;

		if (!mDataChanged) {
			// Try to use an existing view for this position
			child = mRecycler.getActiveView(position);
			if (child != null) {
				// Found it -- we're using an existing child
				// This just needs to be positioned
				setupChild(child, position, x, flow, childrenTop, selected,
						true);

				return child;
			}
		}

		// Make a new view for this position, or convert an unused view if
		// possible
		child = obtainView(position, mIsScrap);

		// This needs to be positioned and measured
		setupChild(child, position, x, flow, childrenTop, selected, mIsScrap[0]);

		return child;
	}

	/**
	 * Add a view as a child and make sure it is measured (if necessary) and
	 * positioned properly.
	 *
	 * @param child
	 *            The view to add
	 * @param position
	 *            The position of this child
	 * @param x
	 *            The x position relative to which this view will be positioned
	 * @param flowDown
	 *            If true, align left edge to x. If false, align right edge to
	 *            x.
	 * @param childrenTop
	 *            Top edge where children should be positioned
	 * @param selected
	 *            Is this position selected?
	 * @param recycled
	 *            Has this view been pulled from the recycle bin? If so it does
	 *            not need to be remeasured.
	 */
	@TargetApi(11)
	private void setupChild(View child, int position, int x, boolean flowDown,
                            int childrenTop, boolean selected, boolean recycled) {
		final boolean isSelected = selected && shouldShowSelector();
		final boolean updateChildSelected = isSelected != child.isSelected();
		final int mode = mTouchMode;
		final boolean isPressed = mode > TOUCH_MODE_DOWN
				&& mode < TOUCH_MODE_SCROLL && mMotionPosition == position;
		final boolean updateChildPressed = isPressed != child.isPressed();
		final boolean needToMeasure = !recycled || updateChildSelected
				|| child.isLayoutRequested();

		// Respect layout params that are already in the view. Otherwise make
		// some up...
		// noinspection unchecked
		AbsHListView.LayoutParams p = (AbsHListView.LayoutParams) child
				.getLayoutParams();
		if (p == null) {
			p = (AbsHListView.LayoutParams) generateDefaultLayoutParams();
		}
		p.viewType = mAdapter.getItemViewType(position);

		if ((recycled && !p.forceAdd)
				|| (p.recycledHeaderFooter && p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) {
			attachViewToParent(child, flowDown ? -1 : 0, p);
		} else {
			p.forceAdd = false;
			if (p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) {
				p.recycledHeaderFooter = true;
			}
			addViewInLayout(child, flowDown ? -1 : 0, p, true);
		}

		if (updateChildSelected) {
			child.setSelected(isSelected);
		}

		if (updateChildPressed) {
			child.setPressed(isPressed);
		}

		if (mChoiceMode != AbsListView.CHOICE_MODE_NONE && mCheckStates != null) {
			if (child instanceof Checkable) {
				((Checkable) child).setChecked(mCheckStates
						.get(position, false));
			} else if (android.os.Build.VERSION.SDK_INT >= 11) {
				child.setActivated(mCheckStates.get(position, false));
			}
		}

		if (needToMeasure) {
			int childHeightSpec = ViewGroup.getChildMeasureSpec(
					mHeightMeasureSpec, mListPadding.top + mListPadding.bottom,
					p.height);
			int lpWidth = p.width;
			int childWidthSpec;
			if (lpWidth > 0) {
				childWidthSpec = View.MeasureSpec.makeMeasureSpec(lpWidth,
						View.MeasureSpec.EXACTLY);
			} else {
				childWidthSpec = View.MeasureSpec.makeMeasureSpec(0,
						View.MeasureSpec.UNSPECIFIED);
			}
			child.measure(childWidthSpec, childHeightSpec);
		} else {
			cleanupLayoutState(child);
		}

		final int w = child.getMeasuredWidth();
		final int h = child.getMeasuredHeight();
		final int childLeft = flowDown ? x : x - w;

		if (needToMeasure) {
			final int childBottom = childrenTop + h;
			final int childRight = childLeft + w;
			child.layout(childLeft, childrenTop, childRight, childBottom);
		} else {
			child.offsetLeftAndRight(childLeft - child.getLeft());
			child.offsetTopAndBottom(childrenTop - child.getTop());
		}

		if (mCachingStarted && !child.isDrawingCacheEnabled()) {
			child.setDrawingCacheEnabled(true);
		}

		if (android.os.Build.VERSION.SDK_INT >= 11) {
			if (recycled
					&& (((AbsHListView.LayoutParams) child.getLayoutParams()).scrappedFromPosition) != position) {
				child.jumpDrawablesToCurrentState();
			}
		}
	}

	@Override
	protected boolean canAnimate() {
		return super.canAnimate() && mItemCount > 0;
	}

	/**
	 * Sets the currently selected item. If in touch mode, the item will not be
	 * selected but it will still be positioned appropriately. If the specified
	 * selection position is less than 0, then the item at position 0 will be
	 * selected.
	 *
	 * @param position
	 *            Index (starting at 0) of the data item to be selected.
	 */
	@Override
	public void setSelection(int position) {
		setSelectionFromLeft(position, 0);
	}

	/**
	 * Sets the selected item and positions the selection x pixels from the left
	 * edge of the ListView. (If in touch mode, the item will not be selected
	 * but it will still be positioned appropriately.)
	 *
	 * @param position
	 *            Index (starting at 0) of the data item to be selected.
	 * @param x
	 *            The distance from the left edge of the ListView (plus padding)
	 *            that the item will be positioned.
	 */
	public void setSelectionFromLeft(int position, int x) {
		if (mAdapter == null) {
			return;
		}

		if (!isInTouchMode()) {
			position = lookForSelectablePosition(position, true);
			if (position >= 0) {
				setNextSelectedPositionInt(position);
			}
		} else {
			mResurrectToPosition = position;
		}

		if (position >= 0) {
			mLayoutMode = LAYOUT_SPECIFIC;
			mSpecificLeft = mListPadding.left + x;

			if (mNeedSync) {
				mSyncPosition = position;
				mSyncColId = mAdapter.getItemId(position);
			}

			if (mPositionScroller != null) {
				mPositionScroller.stop();
			}
			requestLayout();
		}
	}

	/**
	 * Makes the item at the supplied position selected.
	 *
	 * @param position
	 *            the position of the item to select
	 */
	@Override
	public void setSelectionInt(int position) {
		setNextSelectedPositionInt(position);
		boolean awakeScrollbars = false;

		final int selectedPosition = mSelectedPosition;

		if (selectedPosition >= 0) {
			if (position == selectedPosition - 1) {
				awakeScrollbars = true;
			} else if (position == selectedPosition + 1) {
				awakeScrollbars = true;
			}
		}

		if (mPositionScroller != null) {
			mPositionScroller.stop();
		}

		layoutChildren();

		if (awakeScrollbars) {
			awakenScrollBars();
		}
	}

	/**
	 * Find a position that can be selected (i.e., is not a separator).
	 *
	 * @param position
	 *            The starting position to look at.
	 * @param lookDown
	 *            Whether to look down for other positions.
	 * @return The next selectable position starting at position and then
	 *         searching either up or down. Returns {@link #INVALID_POSITION} if
	 *         nothing can be found.
	 */
	@Override
	protected int lookForSelectablePosition(int position, boolean lookDown) {
		final ListAdapter adapter = mAdapter;
		if (adapter == null || isInTouchMode()) {
			return INVALID_POSITION;
		}

		final int count = adapter.getCount();
		if (!mAreAllItemsSelectable) {
			if (lookDown) {
				position = Math.max(0, position);
				while (position < count && !adapter.isEnabled(position)) {
					position++;
				}
			} else {
				position = Math.min(position, count - 1);
				while (position >= 0 && !adapter.isEnabled(position)) {
					position--;
				}
			}

			if (position < 0 || position >= count) {
				return INVALID_POSITION;
			}
			return position;
		} else {
			if (position < 0 || position >= count) {
				return INVALID_POSITION;
			}
			return position;
		}
	}

	/**
	 * setSelectionAfterHeaderView set the selection to be the first list item
	 * after the header views.
	 */
	public void setSelectionAfterHeaderView() {
		final int count = mHeaderViewInfos.size();
		if (count > 0) {
			mNextSelectedPosition = 0;
			return;
		}

		if (mAdapter != null) {
			setSelection(count);
		} else {
			mNextSelectedPosition = count;
			mLayoutMode = LAYOUT_SET_SELECTION;
		}

	}

	@Override
	public boolean dispatchKeyEvent(KeyEvent event) {
		// Dispatch in the normal way
		boolean handled = super.dispatchKeyEvent(event);
		if (!handled) {
			// If we didn't handle it...
			View focused = getFocusedChild();
			if (focused != null && event.getAction() == KeyEvent.ACTION_DOWN) {
				// ... and our focused child didn't handle it
				// ... give it to ourselves so we can scroll if necessary
				handled = onKeyDown(event.getKeyCode(), event);
			}
		}
		return handled;
	}

	@Override
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		return commonKey(keyCode, 1, event);
	}

	@Override
	public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) {
		return commonKey(keyCode, repeatCount, event);
	}

	@Override
	public boolean onKeyUp(int keyCode, KeyEvent event) {
		return commonKey(keyCode, 1, event);
	}

	@TargetApi(11)
	private boolean commonKey(int keyCode, int count, KeyEvent event) {
		if (mAdapter == null || !mIsAttached) {
			return false;
		}

		if (mDataChanged) {
			layoutChildren();
		}

		if (android.os.Build.VERSION.SDK_INT < 11) {
			return false;
		}

		boolean handled = false;
		int action = event.getAction();

		if (action != KeyEvent.ACTION_UP) {
			switch (keyCode) {
			case KeyEvent.KEYCODE_DPAD_LEFT:
				if (event.hasNoModifiers()) {
					handled = resurrectSelectionIfNeeded();
					if (!handled) {
						while (count-- > 0) {
							if (arrowScroll(FOCUS_UP)) {
								handled = true;
							} else {
								break;
							}
						}
					}
				} else if (event.hasModifiers(KeyEvent.META_ALT_ON)) {
					handled = resurrectSelectionIfNeeded()
							|| fullScroll(FOCUS_UP);
				}
				break;

			case KeyEvent.KEYCODE_DPAD_RIGHT:
				if (event.hasNoModifiers()) {
					handled = resurrectSelectionIfNeeded();
					if (!handled) {
						while (count-- > 0) {
							if (arrowScroll(FOCUS_DOWN)) {
								handled = true;
							} else {
								break;
							}
						}
					}
				} else if (event.hasModifiers(KeyEvent.META_ALT_ON)) {
					handled = resurrectSelectionIfNeeded()
							|| fullScroll(FOCUS_DOWN);
				}
				break;

			case KeyEvent.KEYCODE_DPAD_UP:
				if (event.hasNoModifiers()) {
					handled = handleHorizontalFocusWithinListItem(View.FOCUS_UP);
				}
				break;

			case KeyEvent.KEYCODE_DPAD_DOWN:
				if (event.hasNoModifiers()) {
					handled = handleHorizontalFocusWithinListItem(View.FOCUS_DOWN);
				}
				break;

			case KeyEvent.KEYCODE_DPAD_CENTER:
			case KeyEvent.KEYCODE_ENTER:
				if (event.hasNoModifiers()) {
					handled = resurrectSelectionIfNeeded();
					if (!handled && event.getRepeatCount() == 0
							&& getChildCount() > 0) {
						keyPressed();
						handled = true;
					}
				}
				break;

			case KeyEvent.KEYCODE_SPACE:

				if (event.hasNoModifiers()) {
					handled = resurrectSelectionIfNeeded()
							|| pageScroll(FOCUS_DOWN);
				} else if (event.hasModifiers(KeyEvent.META_SHIFT_ON)) {
					handled = resurrectSelectionIfNeeded()
							|| pageScroll(FOCUS_UP);
				}
				handled = true;
				break;

			case KeyEvent.KEYCODE_PAGE_UP:
				if (event.hasNoModifiers()) {
					handled = resurrectSelectionIfNeeded()
							|| pageScroll(FOCUS_UP);
				} else if (event.hasModifiers(KeyEvent.META_ALT_ON)) {
					handled = resurrectSelectionIfNeeded()
							|| fullScroll(FOCUS_UP);
				}
				break;

			case KeyEvent.KEYCODE_PAGE_DOWN:
				if (event.hasNoModifiers()) {
					handled = resurrectSelectionIfNeeded()
							|| pageScroll(FOCUS_DOWN);
				} else if (event.hasModifiers(KeyEvent.META_ALT_ON)) {
					handled = resurrectSelectionIfNeeded()
							|| fullScroll(FOCUS_DOWN);
				}
				break;

			case KeyEvent.KEYCODE_MOVE_HOME:
				if (event.hasNoModifiers()) {
					handled = resurrectSelectionIfNeeded()
							|| fullScroll(FOCUS_UP);
				}
				break;

			case KeyEvent.KEYCODE_MOVE_END:
				if (event.hasNoModifiers()) {
					handled = resurrectSelectionIfNeeded()
							|| fullScroll(FOCUS_DOWN);
				}
				break;

			case KeyEvent.KEYCODE_TAB:
				break;
			}
		}

		if (handled) {
			return true;
		}

		switch (action) {
		case KeyEvent.ACTION_DOWN:
			return super.onKeyDown(keyCode, event);

		case KeyEvent.ACTION_UP:
			return super.onKeyUp(keyCode, event);

		case KeyEvent.ACTION_MULTIPLE:
			return super.onKeyMultiple(keyCode, count, event);

		default: // shouldn't happen
			return false;
		}
	}

	/**
	 * Scrolls left or right by the number of items currently present on screen.
	 *
	 * @param direction
	 *            either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}
	 * @return whether selection was moved
	 */
	boolean pageScroll(int direction) {
		int nextPage = -1;
		boolean down = false;

		if (direction == FOCUS_UP) {
			nextPage = Math.max(0, mSelectedPosition - getChildCount() - 1);
		} else if (direction == FOCUS_DOWN) {
			nextPage = Math.min(mItemCount - 1, mSelectedPosition
					+ getChildCount() - 1);
			down = true;
		}

		if (nextPage >= 0) {
			int position = lookForSelectablePosition(nextPage, down);
			if (position >= 0) {
				mLayoutMode = LAYOUT_SPECIFIC;
				mSpecificLeft = getPaddingLeft()
						+ getHorizontalFadingEdgeLength();

				if (down && position > mItemCount - getChildCount()) {
					mLayoutMode = LAYOUT_FORCE_RIGHT;
				}

				if (!down && position < getChildCount()) {
					mLayoutMode = LAYOUT_FORCE_LEFT;
				}

				setSelectionInt(position);
				invokeOnItemScrollListener();
				if (!awakenScrollBars()) {
					invalidate();
				}

				return true;
			}
		}

		return false;
	}

	/**
	 * Go to the last or first item if possible (not worrying about panning
	 * across or navigating within the internal focus of the currently selected
	 * item.)
	 *
	 * @param direction
	 *            either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}
	 *
	 * @return whether selection was moved
	 */
	boolean fullScroll(int direction) {
		boolean moved = false;
		if (direction == FOCUS_UP) {
			if (mSelectedPosition != 0) {
				int position = lookForSelectablePosition(0, true);
				if (position >= 0) {
					mLayoutMode = LAYOUT_FORCE_LEFT;
					setSelectionInt(position);
					invokeOnItemScrollListener();
				}
				moved = true;
			}
		} else if (direction == FOCUS_DOWN) {
			if (mSelectedPosition < mItemCount - 1) {
				int position = lookForSelectablePosition(mItemCount - 1, true);
				if (position >= 0) {
					mLayoutMode = LAYOUT_FORCE_RIGHT;
					setSelectionInt(position);
					invokeOnItemScrollListener();
				}
				moved = true;
			}
		}

		if (moved && !awakenScrollBars()) {
			awakenScrollBars();
			invalidate();
		}

		return moved;
	}

	/**
	 * To avoid horizontal focus searches changing the selected item, we
	 * manually focus search within the selected item (as applicable), and
	 * prevent focus from jumping to something within another item.
	 *
	 * @param direction
	 *            one of {View.FOCUS_LEFT, View.FOCUS_RIGHT}
	 * @return Whether this consumes the key event.
	 */
	private boolean handleHorizontalFocusWithinListItem(int direction) {
		// TODO: implement this
		if (direction != View.FOCUS_UP && direction != View.FOCUS_DOWN) {
			throw new IllegalArgumentException("direction must be one of"
					+ " {View.FOCUS_UP, View.FOCUS_DOWN}");
		}

		final int numChildren = getChildCount();
		if (mItemsCanFocus && numChildren > 0
				&& mSelectedPosition != INVALID_POSITION) {
			final View selectedView = getSelectedView();
			if (selectedView != null && selectedView.hasFocus()
					&& selectedView instanceof ViewGroup) {

				final View currentFocus = selectedView.findFocus();
				final View nextFocus = FocusFinder.getInstance().findNextFocus(
						(ViewGroup) selectedView, currentFocus, direction);
				if (nextFocus != null) {
					// do the math to get interesting rect in next focus'
					// coordinates
					currentFocus.getFocusedRect(mTempRect);
					offsetDescendantRectToMyCoords(currentFocus, mTempRect);
					offsetRectIntoDescendantCoords(nextFocus, mTempRect);
					if (nextFocus.requestFocus(direction, mTempRect)) {
						return true;
					}
				}
				// we are blocking the key from being handled (by returning
				// true)
				// if the global result is going to be some other view within
				// this
				// list. this is to acheive the overall goal of having
				// horizontal d-pad navigation remain in the current item.
				final View globalNextFocus = FocusFinder.getInstance()
						.findNextFocus((ViewGroup) getRootView(), currentFocus,
								direction);
				if (globalNextFocus != null) {
					return isViewAncestorOf(globalNextFocus, this);
				}
			}
		}
		return false;
	}

	/**
	 * Scrolls to the next or previous item if possible.
	 *
	 * @param direction
	 *            either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}
	 *
	 * @return whether selection was moved
	 */
	boolean arrowScroll(int direction) {
		try {
			mInLayout = true;
			final boolean handled = arrowScrollImpl(direction);
			if (handled) {
				playSoundEffect(SoundEffectConstants
						.getContantForFocusDirection(direction));
			}
			return handled;
		} finally {
			mInLayout = false;
		}
	}

	/**
	 * Handle an arrow scroll going up or down. Take into account whether items
	 * are selectable, whether there are focusable items etc.
	 *
	 * @param direction
	 *            Either {@link android.view.View#FOCUS_UP} or
	 *            {@link android.view.View#FOCUS_DOWN}.
	 * @return Whether any scrolling, selection or focus change occured.
	 */
	private boolean arrowScrollImpl(int direction) {
		if (getChildCount() <= 0) {
			return false;
		}

		View selectedView = getSelectedView();
		int selectedPos = mSelectedPosition;

		int nextSelectedPosition = lookForSelectablePositionOnScreen(direction);
		int amountToScroll = amountToScroll(direction, nextSelectedPosition);

		// if we are moving focus, we may OVERRIDE the default behavior
		final ArrowScrollFocusResult focusResult = mItemsCanFocus ? arrowScrollFocused(direction)
				: null;
		if (focusResult != null) {
			nextSelectedPosition = focusResult.getSelectedPosition();
			amountToScroll = focusResult.getAmountToScroll();
		}

		boolean needToRedraw = focusResult != null;
		if (nextSelectedPosition != INVALID_POSITION) {
			handleNewSelectionChange(selectedView, direction,
					nextSelectedPosition, focusResult != null);
			setSelectedPositionInt(nextSelectedPosition);
			setNextSelectedPositionInt(nextSelectedPosition);
			selectedView = getSelectedView();
			selectedPos = nextSelectedPosition;
			if (mItemsCanFocus && focusResult == null) {
				// there was no new view found to take focus, make sure we
				// don't leave focus with the old selection
				final View focused = getFocusedChild();
				if (focused != null) {
					focused.clearFocus();
				}
			}
			needToRedraw = true;
			checkSelectionChanged();
		}

		if (amountToScroll > 0) {
			scrollListItemsBy((direction == View.FOCUS_UP) ? amountToScroll
					: -amountToScroll);
			needToRedraw = true;
		}

		// if we didn't find a new focusable, make sure any existing focused
		// item that was panned off screen gives up focus.
		if (mItemsCanFocus && (focusResult == null) && selectedView != null
				&& selectedView.hasFocus()) {
			final View focused = selectedView.findFocus();
			if (!isViewAncestorOf(focused, this) || distanceToView(focused) > 0) {
				focused.clearFocus();
			}
		}

		// if the current selection is panned off, we need to remove the
		// selection
		if (nextSelectedPosition == INVALID_POSITION && selectedView != null
				&& !isViewAncestorOf(selectedView, this)) {
			selectedView = null;
			hideSelector();

			// but we don't want to set the ressurect position (that would make
			// subsequent
			// unhandled key events bring back the item we just scrolled off!)
			mResurrectToPosition = INVALID_POSITION;
		}

		if (needToRedraw) {
			if (selectedView != null) {
				positionSelector(selectedPos, selectedView);
				mSelectedLeft = selectedView.getLeft();
			}
			if (!awakenScrollBars()) {
				invalidate();
			}
			invokeOnItemScrollListener();
			return true;
		}

		return false;
	}

	/**
	 * When selection changes, it is possible that the previously selected or
	 * the next selected item will change its size. If so, we need to offset
	 * some folks, and re-layout the items as appropriate.
	 *
	 * @param selectedView
	 *            The currently selected view (before changing selection).
	 *            should be <code>null</code> if there was no previous
	 *            selection.
	 * @param direction
	 *            Either {@link android.view.View#FOCUS_UP} or
	 *            {@link android.view.View#FOCUS_DOWN}.
	 * @param newSelectedPosition
	 *            The position of the next selection.
	 * @param newFocusAssigned
	 *            whether new focus was assigned. This matters because when
	 *            something has focus, we don't want to show selection (ugh).
	 */
	private void handleNewSelectionChange(View selectedView, int direction,
                                          int newSelectedPosition, boolean newFocusAssigned) {
		if (newSelectedPosition == INVALID_POSITION) {
			throw new IllegalArgumentException(
					"newSelectedPosition needs to be valid");
		}

		// whether or not we are moving down or up, we want to preserve the
		// top of whatever view is on top:
		// - moving down: the view that had selection
		// - moving up: the view that is getting selection
		View leftView;
		View rightView;
		int leftViewIndex, rightViewIndex;
		boolean leftSelected = false;
		final int selectedIndex = mSelectedPosition - mFirstPosition;
		final int nextSelectedIndex = newSelectedPosition - mFirstPosition;

		if (direction == View.FOCUS_UP) {
			leftViewIndex = nextSelectedIndex;
			rightViewIndex = selectedIndex;
			leftView = getChildAt(leftViewIndex);
			rightView = selectedView;
			leftSelected = true;
		} else {
			leftViewIndex = selectedIndex;
			rightViewIndex = nextSelectedIndex;
			leftView = selectedView;
			rightView = getChildAt(rightViewIndex);
		}

		final int numChildren = getChildCount();

		// start with top view: is it changing size?
		if (leftView != null) {
			leftView.setSelected(!newFocusAssigned && leftSelected);
			measureAndAdjustRight(leftView, leftViewIndex, numChildren);
		}

		// is the bottom view changing size?
		if (rightView != null) {
			rightView.setSelected(!newFocusAssigned && !leftSelected);
			measureAndAdjustRight(rightView, rightViewIndex, numChildren);
		}
	}

	/**
	 * Re-measure a child, and if its height changes, lay it out preserving its
	 * top, and adjust the children below it appropriately.
	 *
	 * @param child
	 *            The child
	 * @param childIndex
	 *            The view group index of the child.
	 * @param numChildren
	 *            The number of children in the view group.
	 */
	private void measureAndAdjustRight(View child, int childIndex,
                                       int numChildren) {
		int oldWidth = child.getWidth();
		measureItem(child);
		if (child.getMeasuredWidth() != oldWidth) {
			// lay out the view, preserving its top
			relayoutMeasuredItem(child);

			// adjust views below appropriately
			final int widthDelta = child.getMeasuredWidth() - oldWidth;
			for (int i = childIndex + 1; i < numChildren; i++) {
				getChildAt(i).offsetLeftAndRight(widthDelta);
			}
		}
	}

	/**
	 * Measure a particular list child. TODO: unify with setUpChild.
	 *
	 * @param child
	 *            The child.
	 */
	private void measureItem(View child) {
		ViewGroup.LayoutParams p = child.getLayoutParams();
		if (p == null) {
			p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
					ViewGroup.LayoutParams.MATCH_PARENT);
		}

		int childHeightSpec = ViewGroup.getChildMeasureSpec(mHeightMeasureSpec,
				mListPadding.top + mListPadding.bottom, p.height);
		int lpWidth = p.width;
		int childWidthSpec;
		if (lpWidth > 0) {
			childWidthSpec = View.MeasureSpec.makeMeasureSpec(lpWidth,
					View.MeasureSpec.EXACTLY);
		} else {
			childWidthSpec = View.MeasureSpec.makeMeasureSpec(0,
					View.MeasureSpec.UNSPECIFIED);
		}
		child.measure(childWidthSpec, childHeightSpec);
	}

	/**
	 * Layout a child that has been measured, preserving its top position. TODO:
	 * unify with setUpChild.
	 *
	 * @param child
	 *            The child.
	 */
	private void relayoutMeasuredItem(View child) {
		final int w = child.getMeasuredWidth();
		final int h = child.getMeasuredHeight();

		final int childTop = mListPadding.top;
		final int childBottom = childTop + h;

		final int childLeft = child.getLeft();
		final int childRight = childLeft + w;

		child.layout(childLeft, childTop, childRight, childBottom);
	}

	/**
	 * @return The amount to preview next items when arrow srolling.
	 */
	private int getArrowScrollPreviewLength() {
		return Math.max(MIN_SCROLL_PREVIEW_PIXELS,
				getHorizontalFadingEdgeLength());
	}

	/**
	 * Determine how much we need to scroll in order to get the next selected
	 * view visible, with a fading edge showing below as applicable. The amount
	 * is capped at {@link #getMaxScrollAmount()} .
	 *
	 * @param direction
	 *            either {@link android.view.View#FOCUS_UP} or
	 *            {@link android.view.View#FOCUS_DOWN}.
	 * @param nextSelectedPosition
	 *            The position of the next selection, or
	 *            {@link #INVALID_POSITION} if there is no next selectable
	 *            position
	 * @return The amount to scroll. Note: this is always positive! Direction
	 *         needs to be taken into account when actually scrolling.
	 */
	private int amountToScroll(int direction, int nextSelectedPosition) {
		final int listRight = getWidth() - mListPadding.right;
		final int listLeft = mListPadding.left;

		final int numChildren = getChildCount();

		if (direction == View.FOCUS_DOWN) {
			int indexToMakeVisible = numChildren - 1;
			if (nextSelectedPosition != INVALID_POSITION) {
				indexToMakeVisible = nextSelectedPosition - mFirstPosition;
			}

			final int positionToMakeVisible = mFirstPosition
					+ indexToMakeVisible;
			final View viewToMakeVisible = getChildAt(indexToMakeVisible);

			int goalRight = listRight;
			if (positionToMakeVisible < mItemCount - 1) {
				goalRight -= getArrowScrollPreviewLength();
			}

			if (viewToMakeVisible.getRight() <= goalRight) {
				// item is fully visible.
				return 0;
			}

			if (nextSelectedPosition != INVALID_POSITION
					&& (goalRight - viewToMakeVisible.getLeft()) >= getMaxScrollAmount()) {
				// item already has enough of it visible, changing selection is
				// good enough
				return 0;
			}

			int amountToScroll = (viewToMakeVisible.getRight() - goalRight);

			if ((mFirstPosition + numChildren) == mItemCount) {
				// last is last in list -> make sure we don't scroll past it
				final int max = getChildAt(numChildren - 1).getRight()
						- listRight;
				amountToScroll = Math.min(amountToScroll, max);
			}

			return Math.min(amountToScroll, getMaxScrollAmount());
		} else {
			int indexToMakeVisible = 0;
			if (nextSelectedPosition != INVALID_POSITION) {
				indexToMakeVisible = nextSelectedPosition - mFirstPosition;
			}
			final int positionToMakeVisible = mFirstPosition
					+ indexToMakeVisible;
			final View viewToMakeVisible = getChildAt(indexToMakeVisible);
			int goalLeft = listLeft;
			if (positionToMakeVisible > 0) {
				goalLeft += getArrowScrollPreviewLength();
			}
			if (viewToMakeVisible.getLeft() >= goalLeft) {
				// item is fully visible.
				return 0;
			}

			if (nextSelectedPosition != INVALID_POSITION
					&& (viewToMakeVisible.getRight() - goalLeft) >= getMaxScrollAmount()) {
				// item already has enough of it visible, changing selection is
				// good enough
				return 0;
			}

			int amountToScroll = (goalLeft - viewToMakeVisible.getLeft());
			if (mFirstPosition == 0) {
				// first is first in list -> make sure we don't scroll past it
				final int max = listLeft - getChildAt(0).getLeft();
				amountToScroll = Math.min(amountToScroll, max);
			}
			return Math.min(amountToScroll, getMaxScrollAmount());
		}
	}

	/**
	 * Holds results of focus aware arrow scrolling.
	 */
	static private class ArrowScrollFocusResult {

		private int mSelectedPosition;
		private int mAmountToScroll;

		/**
		 * How
		 * {@link it.sephiroth.android.library.widget.HListView#arrowScrollFocused}
		 * returns its values.
		 */
		void populate(int selectedPosition, int amountToScroll) {
			mSelectedPosition = selectedPosition;
			mAmountToScroll = amountToScroll;
		}

		public int getSelectedPosition() {
			return mSelectedPosition;
		}

		public int getAmountToScroll() {
			return mAmountToScroll;
		}
	}

	/**
	 * @param direction
	 *            either {@link android.view.View#FOCUS_UP} or
	 *            {@link android.view.View#FOCUS_DOWN}.
	 * @return The position of the next selectable position of the views that
	 *         are currently visible, taking into account the fact that there
	 *         might be no selection. Returns {@link #INVALID_POSITION} if there
	 *         is no selectable view on screen in the given direction.
	 */
	private int lookForSelectablePositionOnScreen(int direction) {
		final int firstPosition = mFirstPosition;
		if (direction == View.FOCUS_DOWN) {
			int startPos = (mSelectedPosition != INVALID_POSITION) ? mSelectedPosition + 1
					: firstPosition;
			if (startPos >= mAdapter.getCount()) {
				return INVALID_POSITION;
			}
			if (startPos < firstPosition) {
				startPos = firstPosition;
			}

			final int lastVisiblePos = getLastVisiblePosition();
			final ListAdapter adapter = getAdapter();
			for (int pos = startPos; pos <= lastVisiblePos; pos++) {
				if (adapter.isEnabled(pos)
						&& getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) {
					return pos;
				}
			}
		} else {
			int last = firstPosition + getChildCount() - 1;
			int startPos = (mSelectedPosition != INVALID_POSITION) ? mSelectedPosition - 1
					: firstPosition + getChildCount() - 1;
			if (startPos < 0 || startPos >= mAdapter.getCount()) {
				return INVALID_POSITION;
			}
			if (startPos > last) {
				startPos = last;
			}

			final ListAdapter adapter = getAdapter();
			for (int pos = startPos; pos >= firstPosition; pos--) {
				if (adapter.isEnabled(pos)
						&& getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) {
					return pos;
				}
			}
		}
		return INVALID_POSITION;
	}

	/**
	 * Do an arrow scroll based on focus searching. If a new view is given
	 * focus, return the selection delta and amount to scroll via an
	 * {@link ArrowScrollFocusResult}, otherwise, return null.
	 *
	 * @param direction
	 *            either {@link android.view.View#FOCUS_UP} or
	 *            {@link android.view.View#FOCUS_DOWN}.
	 * @return The result if focus has changed, or <code>null</code>.
	 */
	private ArrowScrollFocusResult arrowScrollFocused(final int direction) {
		final View selectedView = getSelectedView();
		View newFocus;
		if (selectedView != null && selectedView.hasFocus()) {
			View oldFocus = selectedView.findFocus();
			newFocus = FocusFinder.getInstance().findNextFocus(this, oldFocus,
					direction);
		} else {
			if (direction == View.FOCUS_DOWN) {
				final boolean leftFadingEdgeShowing = (mFirstPosition > 0);
				final int listLeft = mListPadding.left
						+ (leftFadingEdgeShowing ? getArrowScrollPreviewLength()
								: 0);
				final int xSearchPoint = (selectedView != null && selectedView
						.getLeft() > listLeft) ? selectedView.getLeft()
						: listLeft;
				mTempRect.set(xSearchPoint, 0, xSearchPoint, 0);
			} else {
				final boolean rightFadingEdgeShowing = (mFirstPosition
						+ getChildCount() - 1) < mItemCount;
				final int listRight = getWidth()
						- mListPadding.right
						- (rightFadingEdgeShowing ? getArrowScrollPreviewLength()
								: 0);
				final int xSearchPoint = (selectedView != null && selectedView
						.getRight() < listRight) ? selectedView.getRight()
						: listRight;
				mTempRect.set(xSearchPoint, 0, xSearchPoint, 0);
			}
			newFocus = FocusFinder.getInstance().findNextFocusFromRect(this,
					mTempRect, direction);
		}

		if (newFocus != null) {
			final int positionOfNewFocus = positionOfNewFocus(newFocus);

			// if the focus change is in a different new position, make sure
			// we aren't jumping over another selectable position
			if (mSelectedPosition != INVALID_POSITION
					&& positionOfNewFocus != mSelectedPosition) {
				final int selectablePosition = lookForSelectablePositionOnScreen(direction);
				if (selectablePosition != INVALID_POSITION
						&& ((direction == View.FOCUS_DOWN && selectablePosition < positionOfNewFocus) || (direction == View.FOCUS_UP && selectablePosition > positionOfNewFocus))) {
					return null;
				}
			}

			int focusScroll = amountToScrollToNewFocus(direction, newFocus,
					positionOfNewFocus);

			final int maxScrollAmount = getMaxScrollAmount();
			if (focusScroll < maxScrollAmount) {
				// not moving too far, safe to give next view focus
				newFocus.requestFocus(direction);
				mArrowScrollFocusResult.populate(positionOfNewFocus,
						focusScroll);
				return mArrowScrollFocusResult;
			} else if (distanceToView(newFocus) < maxScrollAmount) {
				// Case to consider:
				// too far to get entire next focusable on screen, but by going
				// max scroll amount, we are getting it at least partially in
				// view,
				// so give it focus and scroll the max ammount.
				newFocus.requestFocus(direction);
				mArrowScrollFocusResult.populate(positionOfNewFocus,
						maxScrollAmount);
				return mArrowScrollFocusResult;
			}
		}
		return null;
	}

	/**
	 * @param newFocus
	 *            The view that would have focus.
	 * @return the position that contains newFocus
	 */
	private int positionOfNewFocus(View newFocus) {
		final int numChildren = getChildCount();
		for (int i = 0; i < numChildren; i++) {
			final View child = getChildAt(i);
			if (isViewAncestorOf(newFocus, child)) {
				return mFirstPosition + i;
			}
		}
		throw new IllegalArgumentException(
				"newFocus is not a child of any of the"
						+ " children of the list!");
	}

	/**
	 * Return true if child is an ancestor of parent, (or equal to the parent).
	 */
	private boolean isViewAncestorOf(View child, View parent) {
		if (child == parent) {
			return true;
		}

		final ViewParent theParent = child.getParent();
		return (theParent instanceof ViewGroup)
				&& isViewAncestorOf((View) theParent, parent);
	}

	/**
	 * Determine how much we need to scroll in order to get newFocus in view.
	 *
	 * @param direction
	 *            either {@link android.view.View#FOCUS_UP} or
	 *            {@link android.view.View#FOCUS_DOWN}.
	 * @param newFocus
	 *            The view that would take focus.
	 * @param positionOfNewFocus
	 *            The position of the list item containing newFocus
	 * @return The amount to scroll. Note: this is always positive! Direction
	 *         needs to be taken into account when actually scrolling.
	 */
	private int amountToScrollToNewFocus(int direction, View newFocus,
			int positionOfNewFocus) {
		int amountToScroll = 0;
		newFocus.getDrawingRect(mTempRect);
		offsetDescendantRectToMyCoords(newFocus, mTempRect);
		if (direction == View.FOCUS_UP) {
			if (mTempRect.left < mListPadding.left) {
				amountToScroll = mListPadding.left - mTempRect.left;
				if (positionOfNewFocus > 0) {
					amountToScroll += getArrowScrollPreviewLength();
				}
			}
		} else {
			final int listRight = getWidth() - mListPadding.right;
			if (mTempRect.bottom > listRight) {
				amountToScroll = mTempRect.right - listRight;
				if (positionOfNewFocus < mItemCount - 1) {
					amountToScroll += getArrowScrollPreviewLength();
				}
			}
		}
		return amountToScroll;
	}

	/**
	 * Determine the distance to the nearest edge of a view in a particular
	 * direction.
	 *
	 * @param descendant
	 *            A descendant of this list.
	 * @return The distance, or 0 if the nearest edge is already on screen.
	 */
	private int distanceToView(View descendant) {
		int distance = 0;
		descendant.getDrawingRect(mTempRect);
		offsetDescendantRectToMyCoords(descendant, mTempRect);
		final int listRight = getRight() - getLeft() - mListPadding.right;
		if (mTempRect.right < mListPadding.left) {
			distance = mListPadding.left - mTempRect.right;
		} else if (mTempRect.left > listRight) {
			distance = mTempRect.left - listRight;
		}
		return distance;
	}

	/**
	 * Scroll the children by amount, adding a view at the end and removing
	 * views that fall off as necessary.
	 *
	 * @param amount
	 *            The amount (positive or negative) to scroll.
	 */
	private void scrollListItemsBy(int amount) {
		offsetChildrenLeftAndRight(amount);

		final int listRight = getWidth() - mListPadding.right;
		final int listLeft = mListPadding.left;
		final AbsHListView.RecycleBin recycleBin = mRecycler;

		if (amount < 0) {
			// shifted items up

			// may need to pan views into the bottom space
			int numChildren = getChildCount();
			View last = getChildAt(numChildren - 1);
			while (last.getRight() < listRight) {
				final int lastVisiblePosition = mFirstPosition + numChildren
						- 1;
				if (lastVisiblePosition < mItemCount - 1) {
					last = addViewAfter(last, lastVisiblePosition);
					numChildren++;
				} else {
					break;
				}
			}

			// may have brought in the last child of the list that is skinnier
			// than the fading edge, thereby leaving space at the end. need
			// to shift back
			if (last.getBottom() < listRight) {
				offsetChildrenLeftAndRight(listRight - last.getRight());
			}

			// top views may be panned off screen
			View first = getChildAt(0);
			while (first.getRight() < listLeft) {
				AbsHListView.LayoutParams layoutParams = (LayoutParams) first
						.getLayoutParams();
				if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) {
					detachViewFromParent(first);
					recycleBin.addScrapView(first, mFirstPosition);
				} else {
					removeViewInLayout(first);
				}
				first = getChildAt(0);
				mFirstPosition++;
			}
		} else {
			// shifted items down
			View first = getChildAt(0);

			// may need to pan views into top
			while ((first.getLeft() > listLeft) && (mFirstPosition > 0)) {
				first = addViewBefore(first, mFirstPosition);
				mFirstPosition--;
			}

			// may have brought the very first child of the list in too far and
			// need to shift it back
			if (first.getLeft() > listLeft) {
				offsetChildrenLeftAndRight(listLeft - first.getLeft());
			}

			int lastIndex = getChildCount() - 1;
			View last = getChildAt(lastIndex);

			// bottom view may be panned off screen
			while (last.getLeft() > listRight) {
				AbsHListView.LayoutParams layoutParams = (LayoutParams) last
						.getLayoutParams();
				if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) {
					detachViewFromParent(last);
					recycleBin.addScrapView(last, mFirstPosition + lastIndex);
				} else {
					removeViewInLayout(last);
				}
				last = getChildAt(--lastIndex);
			}
		}
	}

	private View addViewBefore(View theView, int position) {
		int abovePosition = position - 1;
		View view = obtainView(abovePosition, mIsScrap);
		int edgeOfNewChild = theView.getLeft() - mDividerWidth;
		setupChild(view, abovePosition, edgeOfNewChild, false,
				mListPadding.top, false, mIsScrap[0]);
		return view;
	}

	private View addViewAfter(View theView, int position) {
		int belowPosition = position + 1;
		View view = obtainView(belowPosition, mIsScrap);
		int edgeOfNewChild = theView.getRight() + mDividerWidth;
		setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.top,
				false, mIsScrap[0]);
		return view;
	}

	/**
	 * Indicates that the views created by the ListAdapter can contain focusable
	 * items.
	 *
	 * @param itemsCanFocus
	 *            true if items can get focus, false otherwise
	 */
	public void setItemsCanFocus(boolean itemsCanFocus) {
		mItemsCanFocus = itemsCanFocus;
		if (!itemsCanFocus) {
			setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
		}
	}

	/**
	 * @return Whether the views created by the ListAdapter can contain
	 *         focusable items.
	 */
	public boolean getItemsCanFocus() {
		return mItemsCanFocus;
	}

	@Override
	public boolean isOpaque() {
		boolean retValue = (mCachingActive && mIsCacheColorOpaque && mDividerIsOpaque)
				|| super.isOpaque();
		if (retValue) {
			// only return true if the list items cover the entire area of the
			// view
			final int listLeft = mListPadding != null ? mListPadding.left
					: getPaddingLeft();
			View first = getChildAt(0);
			if (first == null || first.getLeft() > listLeft) {
				return false;
			}
			final int listRight = getWidth()
					- (mListPadding != null ? mListPadding.right
							: getPaddingRight());
			View last = getChildAt(getChildCount() - 1);
			if (last == null || last.getRight() < listRight) {
				return false;
			}
		}
		return retValue;
	}

	@Override
	public void setCacheColorHint(int color) {
		final boolean opaque = (color >>> 24) == 0xFF;
		mIsCacheColorOpaque = opaque;
		if (opaque) {
			if (mDividerPaint == null) {
				mDividerPaint = new Paint();
			}
			mDividerPaint.setColor(color);
		}
		super.setCacheColorHint(color);
	}

	void drawOverscrollHeader(Canvas canvas, Drawable drawable, Rect bounds) {
		final int width = drawable.getMinimumWidth();

		canvas.save();
		canvas.clipRect(bounds);

		final int span = bounds.right - bounds.left;
		if (span < width) {
			bounds.left = bounds.right - width;
		}

		drawable.setBounds(bounds);
		drawable.draw(canvas);

		canvas.restore();
	}

	void drawOverscrollFooter(Canvas canvas, Drawable drawable, Rect bounds) {
		final int width = drawable.getMinimumWidth();

		canvas.save();
		canvas.clipRect(bounds);

		final int span = bounds.right - bounds.left;
		if (span < width) {
			bounds.right = bounds.left + width;
		}

		drawable.setBounds(bounds);
		drawable.draw(canvas);

		canvas.restore();
	}

	@Override
	protected void dispatchDraw(Canvas canvas) {
		if (mCachingStarted) {
			mCachingActive = true;
		}

		// Draw the dividers
		final int dividerWidth = mDividerWidth;
		final Drawable overscrollHeader = mOverScrollHeader;
		final Drawable overscrollFooter = mOverScrollFooter;
		final boolean drawOverscrollHeader = overscrollHeader != null;
		final boolean drawOverscrollFooter = overscrollFooter != null;
		final boolean drawDividers = dividerWidth > 0 && mDivider != null;

		if (drawDividers || drawOverscrollHeader || drawOverscrollFooter) {
			// Only modify the top and bottom in the loop, we set the left and
			// right here
			final Rect bounds = mTempRect;
			bounds.top = getPaddingTop();
			bounds.bottom = getBottom() - getTop() - getPaddingBottom();

			final int count = getChildCount();
			final int headerCount = mHeaderViewInfos.size();
			final int itemCount = mItemCount;
			final int footerLimit = itemCount - mFooterViewInfos.size() - 1;
			final boolean headerDividers = mHeaderDividersEnabled;
			final boolean footerDividers = mFooterDividersEnabled;
			final int first = mFirstPosition;
			final boolean areAllItemsSelectable = mAreAllItemsSelectable;
			final ListAdapter adapter = mAdapter;
			// If the list is opaque *and* the background is not, we want to
			// fill a rect where the dividers would be for non-selectable items
			// If the list is opaque and the background is also opaque, we don't
			// need to draw anything since the background will do it for us
			final boolean fillForMissingDividers = isOpaque()
					&& !super.isOpaque();

			if (fillForMissingDividers && mDividerPaint == null
					&& mIsCacheColorOpaque) {
				mDividerPaint = new Paint();
				mDividerPaint.setColor(getCacheColorHint());
			}
			final Paint paint = mDividerPaint;

			int effectivePaddingLeft = 0;
			int effectivePaddingRight = 0;
			// if ( ( mGroupFlags & CLIP_TO_PADDING_MASK ) ==
			// CLIP_TO_PADDING_MASK ) {
			// effectivePaddingTop = mListPadding.top;
			// effectivePaddingBottom = mListPadding.bottom;
			// }

			final int listRight = getRight() - getLeft()
					- effectivePaddingRight + getScrollX();
			if (!mStackFromRight) {
				int right = 0;

				// Draw top divider or header for overscroll
				final int scrollX = getScrollX();
				if (count > 0 && scrollX < 0) {
					if (drawOverscrollHeader) {
						bounds.right = 0;
						bounds.left = scrollX;
						drawOverscrollHeader(canvas, overscrollHeader, bounds);
					} else if (drawDividers) {
						bounds.right = 0;
						bounds.left = -dividerWidth;
						drawDivider(canvas, bounds, -1);
					}
				}

				for (int i = 0; i < count; i++) {
					if ((headerDividers || first + i >= headerCount)
							&& (footerDividers || first + i < footerLimit)) {
						View child = getChildAt(i);
						right = child.getRight();
						// Don't draw dividers next to items that are not
						// enabled

						if (drawDividers
								&& (right < listRight && !(drawOverscrollFooter && i == count - 1))) {
							if ((areAllItemsSelectable || (adapter
									.isEnabled(first + i) && (i == count - 1 || adapter
									.isEnabled(first + i + 1))))) {
								bounds.left = right;
								bounds.right = right + dividerWidth;
								drawDivider(canvas, bounds, i);
							} else if (fillForMissingDividers) {
								bounds.left = right;
								bounds.right = right + dividerWidth;
								canvas.drawRect(bounds, paint);
							}
						}
					}
				}

				final int overFooterBottom = getRight() + getScrollX();
				if (drawOverscrollFooter && first + count == itemCount
						&& overFooterBottom > right) {
					bounds.left = right;
					bounds.right = overFooterBottom;
					drawOverscrollFooter(canvas, overscrollFooter, bounds);
				}
			} else {
				int left;

				final int scrollX = getScrollX();

				if (count > 0 && drawOverscrollHeader) {
					bounds.left = scrollX;
					bounds.right = getChildAt(0).getLeft();
					drawOverscrollHeader(canvas, overscrollHeader, bounds);
				}

				final int start = drawOverscrollHeader ? 1 : 0;
				for (int i = start; i < count; i++) {
					if ((headerDividers || first + i >= headerCount)
							&& (footerDividers || first + i < footerLimit)) {
						View child = getChildAt(i);
						left = child.getLeft();
						// Don't draw dividers next to items that are not
						// enabled
						if (left > effectivePaddingLeft) {
							if ((areAllItemsSelectable || (adapter
									.isEnabled(first + i) && (i == count - 1 || adapter
									.isEnabled(first + i + 1))))) {
								bounds.left = left - dividerWidth;
								bounds.right = left;
								// Give the method the child ABOVE the divider,
								// so we
								// subtract one from our child
								// position. Give -1 when there is no child
								// above the
								// divider.
								drawDivider(canvas, bounds, i - 1);
							} else if (fillForMissingDividers) {
								bounds.left = left - dividerWidth;
								bounds.right = left;
								canvas.drawRect(bounds, paint);
							}
						}
					}
				}

				if (count > 0 && scrollX > 0) {
					if (drawOverscrollFooter) {
						final int absListRight = getRight();
						bounds.left = absListRight;
						bounds.right = absListRight + scrollX;
						drawOverscrollFooter(canvas, overscrollFooter, bounds);
					} else if (drawDividers) {
						bounds.left = listRight;
						bounds.right = listRight + dividerWidth;
						drawDivider(canvas, bounds, -1);
					}
				}
			}
		}

		// Draw the indicators (these should be drawn above the dividers) and
		// children
		super.dispatchDraw(canvas);
	}

	@Override
	protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
		boolean more = super.drawChild(canvas, child, drawingTime);
		if (mCachingActive /* && child.mCachingFailed */) {
			mCachingActive = false;
		}
		return more;
	}

	/**
	 * Draws a divider for the given child in the given bounds.
	 *
	 * @param canvas
	 *            The canvas to draw to.
	 * @param bounds
	 *            The bounds of the divider.
	 * @param childIndex
	 *            The index of child (of the View) above the divider. This will
	 *            be -1 if there is no child above the divider to be drawn.
	 */
	void drawDivider(Canvas canvas, Rect bounds, int childIndex) {
		// This widget draws the same divider for all children
		final Drawable divider = mDivider;

		divider.setBounds(bounds);
		divider.draw(canvas);
	}

	/**
	 * Returns the drawable that will be drawn between each item in the list.
	 *
	 * @return the current drawable drawn between list elements
	 */
	public Drawable getDivider() {
		return mDivider;
	}

	/**
	 * Sets the drawable that will be drawn between each item in the list. If
	 * the drawable does not have an intrinsic height, you should also call
	 * {@link #setDividerHeight(int)}
	 *
	 * @param divider
	 *            The drawable to use.
	 */
	public void setDivider(Drawable divider) {
		if (LOG_ENABLED) {
			Log.i(LOG_TAG, "setDivider: " + divider);
		}

		if (divider != null) {
			mDividerWidth = divider.getIntrinsicWidth();
		} else {
			mDividerWidth = 0;
		}
		mDivider = divider;
		mDividerIsOpaque = divider == null
				|| divider.getOpacity() == PixelFormat.OPAQUE;
		requestLayout();
		invalidate();
	}

	/**
	 * @return Returns the height of the divider that will be drawn between each
	 *         item in the list.
	 */
	public int getDividerWidth() {
		return mDividerWidth;
	}

	/**
	 * Sets the height of the divider that will be drawn between each item in
	 * the list. Calling this will override the intrinsic height as set by
	 * {@link #setDivider(Drawable)}
	 *
	 * @param height
	 *            The new height of the divider in pixels.
	 */
	public void setDividerWidth(int width) {
		if (LOG_ENABLED) {
			Log.i(LOG_TAG, "setDividerWidth: " + width);
		}
		mDividerWidth = width;
		requestLayout();
		invalidate();
	}

	/**
	 * Enables or disables the drawing of the divider for header views.
	 *
	 * @param headerDividersEnabled
	 *            True to draw the headers, false otherwise.
	 *
	 * @see #setFooterDividersEnabled(boolean)
	 * @see #addHeaderView(android.view.View)
	 */
	public void setHeaderDividersEnabled(boolean headerDividersEnabled) {
		mHeaderDividersEnabled = headerDividersEnabled;
		invalidate();
	}

	/**
	 * Enables or disables the drawing of the divider for footer views.
	 *
	 * @param footerDividersEnabled
	 *            True to draw the footers, false otherwise.
	 *
	 * @see #setHeaderDividersEnabled(boolean)
	 * @see #addFooterView(android.view.View)
	 */
	public void setFooterDividersEnabled(boolean footerDividersEnabled) {
		mFooterDividersEnabled = footerDividersEnabled;
		invalidate();
	}

	/**
	 * Sets the drawable that will be drawn above all other list content. This
	 * area can become visible when the user overscrolls the list.
	 * 
	 * @param header
	 *            The drawable to use
	 */
	public void setOverscrollHeader(Drawable header) {
		mOverScrollHeader = header;
		if (getScrollX() < 0) {
			invalidate();
		}
	}

	/**
	 * @return The drawable that will be drawn above all other list content
	 */
	public Drawable getOverscrollHeader() {
		return mOverScrollHeader;
	}

	/**
	 * Sets the drawable that will be drawn below all other list content. This
	 * area can become visible when the user overscrolls the list, or when the
	 * list's content does not fully fill the container area.
	 * 
	 * @param footer
	 *            The drawable to use
	 */
	public void setOverscrollFooter(Drawable footer) {
		mOverScrollFooter = footer;
		invalidate();
	}

	/**
	 * @return The drawable that will be drawn below all other list content
	 */
	public Drawable getOverscrollFooter() {
		return mOverScrollFooter;
	}

	@Override
	protected void onFocusChanged(boolean gainFocus, int direction,
			Rect previouslyFocusedRect) {
		super.onFocusChanged(gainFocus, direction, previouslyFocusedRect);

		final ListAdapter adapter = mAdapter;
		int closetChildIndex = -1;
		int closestChildLeft = 0;
		if (adapter != null && gainFocus && previouslyFocusedRect != null) {
			previouslyFocusedRect.offset(getScrollX(), getScrollY());

			// Don't cache the result of getChildCount or mFirstPosition here,
			// it could change in layoutChildren.
			if (adapter.getCount() < getChildCount() + mFirstPosition) {
				mLayoutMode = LAYOUT_NORMAL;
				layoutChildren();
			}

			// figure out which item should be selected based on previously
			// focused rect
			Rect otherRect = mTempRect;
			int minDistance = Integer.MAX_VALUE;
			final int childCount = getChildCount();
			final int firstPosition = mFirstPosition;

			for (int i = 0; i < childCount; i++) {
				// only consider selectable views
				if (!adapter.isEnabled(firstPosition + i)) {
					continue;
				}

				View other = getChildAt(i);
				other.getDrawingRect(otherRect);
				offsetDescendantRectToMyCoords(other, otherRect);
				int distance = getDistance(previouslyFocusedRect, otherRect,
						direction);

				if (distance < minDistance) {
					minDistance = distance;
					closetChildIndex = i;
					closestChildLeft = other.getLeft();
				}
			}
		}

		if (closetChildIndex >= 0) {
			setSelectionFromLeft(closetChildIndex + mFirstPosition,
					closestChildLeft);
		} else {
			requestLayout();
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * Children specified in XML are assumed to be header views. After we have
	 * parsed them move them out of the children list and into mHeaderViews.
	 */
	@Override
	protected void onFinishInflate() {
		super.onFinishInflate();

		int count = getChildCount();
		if (count > 0) {
			for (int i = 0; i < count; ++i) {
				addHeaderView(getChildAt(i));
			}
			removeAllViews();
		}
	}

	/*
	 * @Override protected View findViewByPredicateTraversal( Predicate<View>
	 * predicate, View childToSkip ) { View v; v =
	 * super.findViewByPredicateTraversal( predicate, childToSkip ); if ( v ==
	 * null ) { v = findViewByPredicateInHeadersOrFooters( mHeaderViewInfos,
	 * predicate, childToSkip ); if ( v != null ) { return v; }
	 * 
	 * v = findViewByPredicateInHeadersOrFooters( mFooterViewInfos, predicate,
	 * childToSkip ); if ( v != null ) { return v; } } return v; }
	 */

	/*
	 * View findViewByPredicateInHeadersOrFooters( ArrayList<FixedViewInfo>
	 * where, Predicate<View> predicate, View childToSkip ) { if ( where != null
	 * ) { int len = where.size(); View v;
	 * 
	 * for ( int i = 0; i < len; i++ ) { v = where.get( i ).view;
	 * 
	 * if ( v != childToSkip && !v.isRootNamespace() ) { v =
	 * v.findViewByPredicate( predicate );
	 * 
	 * if ( v != null ) { return v; } } } } return null; }
	 */

	/**
	 * Returns the set of checked items ids. The result is only valid if the
	 * choice mode has not been set to {@link #CHOICE_MODE_NONE}.
	 * 
	 * @return A new array which contains the id of each checked item in the
	 *         list.
	 * 
	 * @deprecated Use {@link #getCheckedItemIds()} instead.
	 */
	@Deprecated
	public long[] getCheckItemIds() {
		// Use new behavior that correctly handles stable ID mapping.
		if (mAdapter != null && mAdapter.hasStableIds()) {
			return getCheckedItemIds();
		}

		// Old behavior was buggy, but would sort of work for adapters without
		// stable IDs.
		// Fall back to it to support legacy apps.
		if (mChoiceMode != AbsListView.CHOICE_MODE_NONE && mCheckStates != null
				&& mAdapter != null) {
			final SparseArrayCompat<Boolean> states = mCheckStates;
			final int count = states.size();
			final long[] ids = new long[count];
			final ListAdapter adapter = mAdapter;

			int checkedCount = 0;
			for (int i = 0; i < count; i++) {
				if (states.valueAt(i)) {
					ids[checkedCount++] = adapter.getItemId(states.keyAt(i));
				}
			}

			// Trim array if needed. mCheckStates may contain false values
			// resulting in checkedCount being smaller than count.
			if (checkedCount == count) {
				return ids;
			} else {
				final long[] result = new long[checkedCount];
				System.arraycopy(ids, 0, result, 0, checkedCount);

				return result;
			}
		}
		return new long[0];
	}

	@Override
	public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
		super.onInitializeAccessibilityEvent(event);
		event.setClassName(HListView.class.getName());
	}

	@TargetApi(14)
	@Override
	public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
		super.onInitializeAccessibilityNodeInfo(info);
		info.setClassName(HListView.class.getName());
	}

	@Override
	public void onGlobalLayout() {
	}
}
